The G1 smartphone went live this morning and software in Google’s Android Market is available for free, lasting for an unspecified limited time, officials said today.

G1 is the first device running the Google Android operating system, which also as of today is available in open-source code.

In addition, T-Mobile opened a customer discussion forum – that should be useful because around half of G1 pre-orders were from customers who only owned a feature phone, the operator noted.

No other mobile device since the original Apple iPhone has garnered so much attention. Experts believe Android could change the industry because it merges the credibility of a massive software company and the flexibility of Linux. Apple brings applications and hardware design credibility but is limited by its closed-source approach, while previous Linux efforts only found modest success.

For its part, T-Mobile is continuing to open more 3G regions, although the company behind-the-scenes is engaged in a battle over spectrum that some believe could lead to signal interference from other systems.

Kyocera said it too will also make a series of Android phones, with at least one model due next year. The company will partner with software specialist Wind River.

Also today, Texas Instruments contributed its Bluetooth and WLAN code to the Android project.