iPhone 3G Battery Replacement
Great instructions, very clear. A couple points:
1) The screwdriver I had wasn't working that well, so I had to use a different one. I found that a 0# worked fine (although I suspect a 00# would work better.0
2) When I reassembled the phone, the home button didn't work. You really need to press down on the bottom of the screen when you screw the bottom screws (by the dock connector) back in. Otherwise, the contacts for the home button won't reliably hit.