Originally Posted by timbuk2
Quicksettings is a nice, free app for one click access to toggle things like GPS, WiFi, Bluetooth (And data, but it does the APN trick, so I don't use it for that),
What is the APN trick?
Some data toggles change the name of the APN that the phone connects to. This keeps the phone from connecting, turning data "off", but keeps power running to the 3G radio, which doesn't actually save you any battery.
I have since discovered that QuickSettings does things the proper way, and I have gone back to using it to toggle my data.
timbuk2, hope some of this stuff is the same for you. The general guidelines are all there. I'm glad to see this thread is helping some people.