"Experience the first Android-powered phone from T-Mobile..." That's pretty much all our invitation to this long-awaited announcement told us. So you'd better believe that we'll be there in person to get the news first-hand, and live blog the event! Come back Tuesday, September 23, at 10:30 A.M. EST (or even a bit earlier) to experience the Android launch as it happens.

In case you've been avoiding all tech news for the past year, the long-awaited Android (being developed by The Open Handset Alliance) is is a Linux-based, open operating system for mobile phones that will feature Google apps. Basically, it will make developing third-party apps quicker and easier--though how open the actual phones are is up to the phone makers and wireless carriers.

Here are a couple columns from PCMag.com for preliminary reading:

Google Android: Prepare to Be Underwhelmed. Lance Ulanoff asks, "Do we really need another phone platform and cascade of proprietary apps?"

T-Mobile's Dream Is a Distraction. Sascha Segan asserts, "Google's Android OS is really about ruling the world of feature phones, not the world of smartphones."

10:10: Live blog starting now! After the jump.

We've arrived at the location and it's filling up with press. There are four stools in front of a flat-screen TV, and a sort of fashion catwalk jutting out into the crowd.

T-Mobile confirmed that the G1 will be available to existing T-Mobile customers today for pre-order. Phones will be delivered on Oct. 22.

Third party applications will be available through Android Marketplace as soon as the phone launches, T-Mobile confirms. We'll see some of those later, too.

Mobile data revenues up by 43%, traffic grown by 250%. All this openness stuff goes against what Dotson said at CTIA, amusingly.

The official fact sheet is out. The phone will come in white, brown and black. They're advertising four apps at launch in the "beta" version of Android Market: "ShopSavvy," a comparative shopping app; "Ecorio" which helps you manage your carbon footprint (?), "BreadCrumbz," a GPS route tracker, and the Amazon MP3 store.

10:30--The event is starting!

Nonsensical video montage of T-Mobile global love. Introducing T-Mobile's CTO. [Cole Brodman]

He is saying technology has bridged the gap between people. We haven't been able to rely on the integration between the Internet and the mobile phone to bring us together. This is a platform, a system, a device and a set of services.

Andy Rubin is here. Also Peter Chou from HTC. Applause.

Guy from DT is kicking things off. Strong tradition of being pioneers of the open mobile Internet, Launching first Android based mobile phone, T-Mobile G1. Exclusive.

Launching it on both sides of the Atlantic. Bringing device to market at the end of this year as promised.

Now we're going through the history of "opening up the mobile Internet." They're saying they moved away from walled gardens in 2005 and they're so proud of themselves. "The mobile Internet is the dominant trend of our industry going forward."

Mobile data revenues up by 43%, traffic grown by 250%. All this openness stuff goes against what Dotson said at CTIA, amusingly.

T-Mobile Intl is committed to open industry platforms as they bring the necessary freedom to our customers. T-Mobile G1 is a milestone etc etc.

And now ... Andy Rubin

Android is bringing Google advances and strategies to the mobile phone. Developers will be able to use it as a platform and developers will be able to modify the platform, make the platform better. Because it is open, it's future-proof.

Peter Chou from HTC. Hard to understand what he's saying, but it's pretty much the same stuff. There was a tremendous effort to make OHA happen.

HTC has worked closely with Google and T-Mobile to develop a unique, iconic design unlike anything else in the market that would maximize the mobile internet experience. With impressive touch experience and a cool ... keyboard, the T-Mobile G1 will appear to a broad variety of people.

CTO guy again. Mobile broadband has been available for a while, it's applications and devices that have been lacking. US consumers have an appetite for mobile Internet, but penetration lags at a dismal 16% in the US. Problem: lack of compelling experiences.

"We're going to lean into open systems, open standards - we're going to lean into great partnerships... No more fuzzy pictures on the Internet ... no more unsubstantiated blog posts."

Extremely high speed video of Android usage which makes it look like it works very similarly to an iPhone. But looks like a Sidekick. Ah, T-Mobile.

CTO guy: "They'll have lots of devices for us to play with live." Oh yes, they will.

And now a demo. Swipe for multiple virtual desktops. Tap, etc. One-click ordering on Amazon. Long presses take you deeper into things. G1 multitasks.You drag down window-shades for alerts and menus.

Click from an address to go straight to Google Maps. Directions and traffic view.

Menu button on Street View enables Compass Mode, which shows the direction you're facing.

Multiple Web page support in browser. Dedicated Google search button on keyboard. Search is always relevant to your context: addresses or Web.

It comes loaded with applications. Android market comes with user ratings and reviews on profile pages.

CTO: Open development environment and third-party application partners are key.

Price will be $179 with two-year contract.

This platform will embrace change by allowing third parties to write apps that serve human needs and technology advances. We believe third parties will drive innovation, etc. And now a video.

Dull and self-affirming video interviews with ShopSavvy developers. Basically pointless self-back-patting. [Heh! --Ed.]

Ecorio developer says you don't have to sign up for an SDK or pay any amount of money. ShopSavvy developers are saying, "There's no third party who are saying you can't do that." Take that, App Store!

The Ecorio and ShopZilla developers all look like college students. Initial profits to be invested in Accutane.

CTO: "Ecorio carbon footprint guys are here. They are, in fact, sitting a row in front of me. Four young guys with identical haircuts."

ShopSavvy turns G1 into barcode scanner. You scan items on shelves and it gives you comparative pricing back.

Q&A starts.

Pricing and availability? $179. Avail for existing customers starting today. Commercial launch Oct 22. Selected stores, markets, etc. Two plan options: $25 unlimited Web/Internet and some messaging, $35 unlimited data and messaging.

[That's more expensive than the existing $19.99 plan for smart phones.]

3G is up live in 16 markets. Live in 22 markets by launch. Live in 27 markets by end of November. Will cover 80% of T-Mobile cities.

Christopher from DT: They want to launch in Europe for their 100m customers. Device will be available in UK early Nov, across Europe in 1Q 2009.

Andy Rubin: They will open source the entire platform, etc. Long-tail platform.

Question: Will it work as tethered modem, and is pricing on top of voice plan? Answer: No tethering. Data plan will require a voice plan.

Question: MS Office and Exchange support? Locked to T-Mobile? Answer: Can read Word, PDF and Excel. No Exchange compatibility but third parties can go there. It will be locked.

Question: Push email or just IMAP? Answer: Gmail is push. IMAP is pull.

Question: Desktop syncing app? Answer: All syncing OTA.

Question: Available in EDGE markets? Answer: Avail in all markets but best experience on 3G. Good experience on 2G, best experience on Wifi and 3G.

Question: Unlocking! Unlocking! Answer: No guarantees in technology, but $179 is an attractive price and the device costs quite a bit more than that. In other words, let 'em make back their subsidies ...

Question: Will Google help with marketing? Answer: You betcha. Google properties will be involved. Biggest marketing campaign they've ever launched.

Question: Server sync like Sidekick? What BT profiles - A2DP and keyboard? Answer: Syncs with Google services. BT: Headset and handsfree only. A2DP in future.

Question: Chrome browser? Answer: Webkit browser has same base as Chrome, but this is a different implementation; call it "Chrome lite."

Question: Who is this for? Answer: This device is going to have mass appeal. But more a consumer device than an enterprise device. Enterprise workers will buy it individually, though.

Question: Will Gmail be better than it is on the iPhone? Answer: It's a robust Gmail experience, threading, archiving, labels, searching. First implementation of online presence inside the phone book for Google Talk.

Question: iTunes and Skype? International roaming? Answer: It will work with any AAC, WMA, MP3, etc. music. iTunes content must be NOT protected. No Skype yet. Yes, it roams internationally.

Special guests! Larry Page and Sergey Brin! One of them is on rollerblades. I don't know what each of them looks like. No, both of them are on rollerblades.

Google founder is a geek, he says. Stop the presses!

He wrote an Android app that measures how much time the phone spends in the air if you toss it up in the air, using the accelerometer.

It's exciting to him to have a phone he can modify like a computer.

The other founder says he's excited about the possibilities this means. 3 billion mobile phones, a billion new ones each year. This is a pretty good computer.

I think the Google founder just asked people to try to do Web searches using only their brains. There was something lost in translation there. In any case, he says having PC like functionality on a phone is good. We needed a special guest to say that?

LBS will be big.

Hideous scrumlike photo op.

It's over!

[Sascha is going immediately for in-person demos. Look for his first takes and reviews on PCMag.com!]