If you’re like many iPhone users, you suck the power out of your battery completely about once every 24 hours. The more useful a thing is, the more you use it–hence, my iPhone’s battery tends to be more empty than full. Here’s what to do to keep that battery alive:

1. Disable 3G. Bar none, this is the single most effective way to increase battery life on the iPhone. If you can tolerate the slowness of Edge and you don’t use any realtime data apps (like VoIP stuff, say), then Edge should be sufficient. You’ll probably have fewer dropped calls with Edge too.

2. Turn off WiFi and Bluetooth. Unless you’re using them, WiFi and Bluetooth are battery killers. Besides, the gimpy-ness of the iPhone’s Bluetooth support makes me question why anybody would leave it on at all.

3. Decrease the frequency of e-mail checks. This will result in fewer data transmissions and preserve the battery.

4. Install the 2.2 firmware update. Apparently, it helps.