I guess there are some pretty wildly different battery results from people. I've had my phone on with its original charge for 3 1/2 days. I don't yet have a sim card but I left the antenna on to see how it affects the battery. I've been using the phone a lot on my home WIFI though. In total, my screen has taken 8% of the battery life and 90% has been eaten up by cell-standby. That is in stark contrast to what most people have been reporting (50-60% of battery life going into powering the screen). I'm probably using the screen a tad bit less than others but I have been using it a lot. Hopefully this indicates that my battery will last a hell of a long time once I actually have the sim (which I'm getting on Monday!
).