T-Mobile 3G coverage expanding to accommodate G1
As you may know, many of the innovative apps and services on the new Google Android phone, the T-Mobile G1 have been optimised for use on T-Mobile’s 3G network or Wifi, and T-Mobile is expanding their network further to take in more areas.
This means if you live in an area with 3G coverage or access to WiFi then the G1 should work fine, but if you don’t live in a 3G area the G1 still has many popular functions you can enjoy.
If you aren’t covered by 3G, T-Mobile’s EDGE network still offers a moderate-speed data service and many G1 features will work on EDGE just as satisfactorily.
Source — T-Mobile G1