For T-Mobile G1, there will be a bundle of g1 accessories online to select from; everything from Backup Batteries to Car Accessories, G1 Cases, Chargers, Cables, Headphones, Cradles, Bluetooth Accessories, and more. The list goes on and on, but basically the primary purposes of any tmobile g1 accessories are to add functionality, such as where you can use it and what you can use it with, make some features easier to use, and extend the use of the G1 Android phone.