Just as a reminder post:
I traced my battery drainage problem to my GoPhone sim without a data plan. Once I removed the sim, the battery would last a few days. Put the sim in, the battery would drop 1% every few minutes.
I would put my real iPhone sim in and the battery life was normal. Put the GoPhone sim back in and the battery life would drop again like above. I tested this on a 1st generation, 3G and the 3GS, same problem on all.
Yea... but if I'm unlocked, this doesn't apply to me or anyone that is unlocked...