ExAF's reply just reminded me about the WiFi/battery thing.

I find the same problem (it's trying to connect all the time) when I'm out and about, so I turn off the WiFi when I'm on a walkabout, or better yet, if I know I'm not going to be making/taking calls, I'll put it in 'Airplane Mode' just to keep it from searching for towers if I'm driving/flying through the outback with no way to charge it, or when on a layover in Tokyo, etc.

That will save the battery for later, when you might need it. My EVO will stay charged for a good 24 hours or more when I leave it in Airplane Mode. The GPS will still work for mapping.