Mount your portable navigation device on the dashboard or suction-cup it to the windshield in Minnesota or California, and you could be cited. Laws that forbid windshield obstructions are being reinterpreted, or rewritten, to cause problems for motorists who want to know where they're going.

According to Telematics Update, Minnesota law forbids affixing anything to the windshield other than "sun visors and rearview mirrors and electronic toll collection devices," which leaves open the issue of a device affixed to the dash that's near the windshield. And California law now forbids any device "applied in or upon the vehicle which obstructs or reduces the driver's clear view through the windshield or side windows."

Navigation-system makers are concerned enough to post warnings on their Web sites. So far that includes TomTom, Garmin, and Thales Navigation.

Windshield obstruction laws have occasionally been applied to radar-detector owners, but not frequently. The laws aren't applied enough to people with fuzzy dice, garters, and graduation tassels that sway from rearview mirrors. Those are a safety hazard, because the motion anesthetizes your eye in that region, and you're less likely to notice other motion, such as a kid darting out from the curb or a car running a stop sign.

Telematics Update wondered if head-up displays such as the dazzling device on the BMW 650i that show images at the base of the windshield could be in for hard times. Brad Warner, project leader of Siemens VDO's Corporate Communications & Media Relations division, said HUDs are legal in all states, since they don't actually appear on the windshield but reflect off the base of the windshield and appear to float just above the hood. (And as a practical matter, the HUD can't be seen from outside the car.)

This is another law that seems to suggest the best legislatures are the ones that meet for the least time. Here's what wrong:

Vague parameters. There may be no clear distinction between a device that merely sits in the windshield and one mounted so high as to obscure your line of sight. The line of sight behind a low-mounted device obscures your view of the middle of the hood, not the road ahead, unless you're 4-foot-8 and peering through the steering wheel.

Possible selective enforcement. If police don't like young kids cruising and enjoying themselves but otherwise appearing to abide by the law, now, in addition to the usual reasons for stopping a car (burned out taillights, lane changes without signaling, driving 6 mph over the limit) there's one more tool that will probably net one drug dealer out of every 100 stops, two expired registrations, five missing licenses or registrations, and a disproportionate amount of annoyed, mostly youthful people of color. Most cops are decent guys who try to temper the law with wisdom. Others aren't.

Cops are exempted. You don't think they'd cite themselves for driving with radar guns, shotguns, donut boxes, unmarked car gumball flashers, or uniform hats on the dashboards or clipped in the line of sight through the windshield, do you?

The law is too sweeping. Taken to an extreme, the obstruction law could pertain to your garage door opener clipped to the sun visor if part of it droops down, the tiny satellite radio receiver on the dash, a small tethered GPS antenna (for your laptop) affixed to the base of the windshield, the occasional manufacturer's GPS antenna mounted permanently in the upper corner of the windshield, or the Audi A8 Bang & Olufsen Advanced Sound System tweeters that actually rise out of the dash. There must be others; post your most outlandish possibilities in the thread below.

The world won't change much either way, with laws like this. The Bill of Rights hasn't been repealed. But it's an unnecessary hassle for people who find plenty of value in a $500 portable navigation device over an $1,800 built-in nav system.

To read more about the best (cheap) tech upgrades, click here.

Here's another Gearlog mystery.

The other day I was on my way to the train station when I found myself walking behind this guy with a messenger bag. This wasn't an ordinary bag, though; it contained two stereo speakers on each side, and what looked like volume controls underneath them. He was holding an MP3 player connected to his headphones.

So, I took my Sanyo PM 8200 camera phone out and snapped a shot. What I'm trying to figure out is what the heck is this audio bag?! I know that Blogging Molly owns the Techwiz Musak Notebook Carrying Case, which lets you connect your iPod and listen to your tunes through the bag's speakers. But, this isn't it.

So c'mon Gearlog readers: clue me in on what you think this audio bag is called! Here's another pic.

(Click on the image for a larger view.)

Mind you, I would've taken an even closer shot of the bag, but I didn't want this guy to think I was hitting on him (or checking out his NAS).

If you're in Manhattan today, or at least in the Tri-State area, then you know it's horribly hot outside. I decided that because of the harsh heat today, that I would test Q3 Innovations' UV Hawk. The UV Hawk is a device that formulates how long you can be out in the sun before you burn (with both a countdown and max. exposure limit), based on temperature, UVI, skin type, and the SPF you're wearing. It can detect a UVI up to 15 and an SPF range of 0-100. The UV Hawk weighs just 2 ounces, measures 2.3 x 1.2 x 0.5 inches, and operates on a CR2016 battery.

I grabbed my sunglasses and braced myself as I walked outside of our office building around 1:15 pm into what felt like a pizza oven. I stood directly in the sunlight, powered the device, and within 3 seconds, the UV Hawk's sensor calculated that it was 103 degrees out with a UVI of 6. However, according to weather.com, the UVI was 7 for Manhattan.

I pressed the SPF/Skin button and then the Meas./Adj. button to punch in what SPF level I was wearing, which was 35. (I wasn't really wearing any sun block, but the device didn't know that!) I then pressed the SPF/Skin button again to put in my skin setting, which was 2.

The UV Hawk is based on four skin tone levels:

Level 1: Pale or milky, white alabaster skin. Typically get burned with peeling
Level 2: Very little brown, sometimes freckles. Typically get burned with pink or red areas, but sometimes get a light brown tan.
Level 3: Light brown or olive skin. Sometimes get sunburns but tans at a moderate rate.
Level 4: Darker brown or black skin. Rarely gets sunburned and tans at a rapid rate.

Next, the device calculates how long you can be out in the sun until you get burned. Here are my results:

With a UVI of 6, SPF of 35, and Skin type 2, I can stay in the sun for 25 minutes and 16 seconds. The device will countdown until zero, and then sound an alarm when I've reached my limit.

I tried this three more times to account for other skin types:

Skin Type 1:
UVI 6
SPF 20
103 degrees
7m:13s

Skin Type 3:

UVI 6
SPF 25

103 degrees
27m:05s

Skin Type 4:

UVI 6
SPF 10
103 degrees

14m:26s

During testing, I wasn't sure if the percentage of maximum exposure limit was correct. When I tested for skin type 2, it gave me an 8% maximum exposure. For the other skin types, it gave me 0%. I will try to clarify this from the company.

Overall: The UV Hawk will definitely come in handy while you're at the beach or just lounging out by the pool. I never know how long I can stay out in the sun before I get burned. Although you shouldn't use this device as the most accurate indicator of UV rays, it's still a very useful gadget to have for the remaining weeks of summer!

Purchase the UV Hawk for $44.99 at SmartHome.com.

Yesterday, Abcron Corp. introduced the Stereo Memory Foam Pillow. It features a stereo sound system that lets you connect an MP3 player, CD player, even an alarm clock so you can listen to tunes while falling asleep. It's made out of memory foam to ease discomfort. 

Stereo pillows aren't really anything new. But when Gearlogger Dan Costa saw this, he had a few suggestions of his own:

What it needs is an AROMA-module, which time-releases a soothing scent as you sleep. I am thinking Ocean Wind or Pine Forest Breeze. AROMA-modules can increase the quality and quantity of restful REM sleep by 43 percent!

Not a bad idea! I don't think I'd be able to fall asleep listening to music; the TV sometimes, but music--nope!

The Stereo Memory Foam Pillow is available for $39.99 at www.wonderfulbuys.com.

Thanks to Gearlogger and PC Mag Executive Editor Jeremy Kaplan for the tip!

The Sony Micro Vault Tiny packs up to 2GB of storage into a thumbnail-size USB flash drive. (It's half the size of the picture at right, around an inch long). I tested the 1GB, translucent-blue model. It comes with a neat little carrying pouch, which you'll need: Losing this miniscule device would be tragic (and all too easy).

The Micro Vault comes with Virtual Expander software installed: It crunches the files you copy to the flash drive, freeing storage room and giving you virtually three times more space, according to Sony. You can enable Virtual Expander to compress files automatically and decompress them when you copy them to another drive. When I loaded files on the Tiny, Virtual Expander compressed a 140KB Word document down to 14KB and a 50KB Excel spreadsheet to 10KB. but it hardly touched images or executable files; it might knock off a few kilobytes, but not much more. And of course, you still have up to 2GB to play with.

Sony sells the 1GB version for $ 64.99 on their Web site; the 2GB version is $109.99. (It also comes in smaller sizes.)

Thanks to intern Errol Pierre-Louis for this review!

If you're not familiar with PodBrix, like me, then you'll need to know that it's a Maryland-based Web site that sells "minifigs" (aka small, plastic Lego people) inspired by popular music player ads. Tomi, the creator, has designed many limited editions of minifigs, such as the 1K Brix Macrofig that stands over 7 inches tall, and the Wozwear 6502 Shirt showing Woz holding an actual 6502 processor chip.

Why are Tomi's creations so cool? Because who doesn't like Legos! Plus, each minifig is sold in limited quantities and they sell fast.

Going on sale tonight at 9 pm EST is the 1984 Playset ($198.99). Inspired by the classic 1984 Apple TV commercial ("We Shall Prevail!"), this limited set was designed with over 80 parts and includes "an intricately detailed 'runner' minifig, two riot police minifigs and an audience of twelve figures...A static LED backlit movie screen complete with a minifig style 'Big Brother' completes the effect."

I have to say, it's a fairly accurate portrayal of the commercial! PodBrix will sell only 100 units, so get your mouse finger ready. Three AA batteries are required to power the LED screen.

The site doesn't offer much more information than what I've told you about the 1984 Playset, other than some answers to FAQs:

What are the concrete side-walls constructed from?

The walls are made from heavy card stock printed with a concrete pattern.

Will you ship the 1984 Playset internationally?

Yes. We ship via standard Air Mail to almost any country. Shipping rates will be listed during checkout.

Thanks to Ben Gottesman for the tip!!