Seidio now has a selection of extended life batteries available for the G2X:
Innocell 1750mAh Slim Extended Life Battery
Innocell 3200 mAh Slim Extended Life Battery
I've got one of the later on the way, review pending.
Innocell 1750mAh Slim Extended Life Battery
Innocell 3200 mAh Slim Extended Life Battery
I've got one of the later on the way, review pending.