I cannot take credit for this as it's mentioned in multiple threads here, I would just like to bring it to the attention of anyone that doesn't already know. Disabling APN when not required has allowed my phone to run for 3 days and still be at 70% battery. To disable APN I installed the app WiSyncPlus from the app store. This app can be used for controlling network/data access on your phone in multiple ways, but all I use is the very simple APN toggle widget. I only toggle APN on when I require data access for web/email/market etc. then switch it straight back off. When APN is off you can still use the handset as an old school phone, for calls and texting, but not mms. There are multiple options in this app for controlling syncing etc. very much worth a look if you use your phone for email too. I also have my Samsung switchers widget app next to the APN widget, so if I have a wifi connection available I use this instead of enabling APN to surf the web etc. There is also a free app called APNDroid that can disable APN but I haven't tried this so can't comment on it's usability. One last thing though, some of these APN apps stress that you should enable APN before uninstalling/updating the app or you could lose your APN settings completely, so please remember to do this. Also, I don't have any self-updating widgets on my Home screen, just lots of shortcuts to open the apps instead. At last I can get longer battery life from my Samsung Galaxy than I could from my N95, charging everyday was putting me off big time before discovering this app. Big thanks to the developer of WiSyncPlus.