Many Wi-Fi detectors have appeared over the years. They're usually cheap (or even free) but capable only of telling you there's something in range with a little roving red Cylon-esque LED that might give an indication of signal strength. The detector to beat has for years been the Canary Wireless Digital Hotspotter, with its display screen that indicates signal strength, network SSID, and whether the network is encrypted. Other detectors with similar info screens tend to be USB-based and double as laptop Wi-Fi adapters, pushing the prices much higher.
Looks like Canary Wireless will be one-upping itself. The company has announced a new Hotspotter, coming soon.
The Canary HS20 will continue to provide the information noted above but adds a differentiation between 802.11b, 11g, and even 11n networks using the 2.4-GHz radio frequency (it won't detect 5-GHz 802.11a or 11n connections that utilize 5 GHz, nor will it see Bluetooth signals).
This Hotspotter also sniffs packets to estimate how fast the network performs. Nice.
It will have three buttons instead of the one on the original Hotspotter, so users can actively turn the device off and on and cycle through all the available networks to see which is worth a piggyback ride (Note: you shouldn't piggyback without permission, it's rude and could be illegal). It runs on just a couple of AAA batteries.
If there was a downside to the original Hotspotter, it's that it was a bit too thick to keep in a pocket or on a key ring. The new version is just over half an inch thick, but it's still 3 inches high, so it still probably isn't as portable as it could be. The high price of $59.95 also means it's going to be limited to serious Wi-Fi-using road warriors, but the cost could be worth it, since you'll be able to avoid booting up the laptop just to see if there's a slim chance you can get some wireless access.
[via Wi-Fi Networking News]