I started experiencing horrible battery life and realized the problem was my phone was never sleeping. The phone kept thinking it was on the charger when it wasn't.
Excellent! The pictures were a great help and everything went much as described. I did have a little trouble getting the power button cable reattached, but once you've taken it apart, the second time goes much faster. :)
From reading the comments, be very sure you have the CDMA version. If you have the GSM version, read up before you dig in!