I was quite frustrated earlier with my battery performance. I turned off: - WiFi - Bluetooth - "Use wireless networks" - Gmail/Email pull and Auto-sync (but leave the "Background data" on) - "Enable GPS satellites" - Weather update - "Enable Always-On mobile" (but leave the "Mobile network" ticked) - and let Twitter/Facebook to automatically update only once/twice a day. Still the battery was draining very fast. The only thing I did not turn off is the 3G. Yesterday I decided to switch to 2G and replace the built-in SMS with Handcent SMS. To my very surprise, the battery life improves greatly. I will now do a test to see how fast it drains. I have just fully charged the unit and will update it here once I get the result.