What’s this I hear about being able to turn a T-Mobile G1 into an Android Developer Phone?
Excluding cosmetic differences, the two differences are the radio lock and the enhanced bootloader. The radio lock can be removed with a simple request to T-Mobile. That only leaves the bootloader as the major difference. There currently is a bootloader floating in the wild, that seems to be very similar to what is expected to be running on the ADP1 (Android Dev Phone 1).
The catch is you can only install this boot loader if you are one of the lucky few that has a "rooted" G1. This means that you are out of luck if you are running a stock version of RC30+. See [http://www.gotontheinter.net/node/7](http://www.gotontheinter.net/node/7) for details. If your phone is not rooted but above RC30 it is still possible to root your phone by downgrading to the insecure version and then re-upgrading with a patched firmware update. See: [Root For RC30](http://android-dls.com/wiki/index.php?title=Root_For_RC30)