If your idle phone is eating up battery, try this. Install CPU Spy from market. Open it. The menu button will let you reset your stats or refresh the display. You may need to tap the menu button and choose "refresh" if you just woke your phone with the app open. I haven't used my phone much since I pulled it off the charger this morning and it reports it's been deep sleeping for 86% of the time. Deep sleep is where you'll get the best idle battery life. If you're not getting deep sleep, with certain custom roms (like CM7) here's what you can do: Install spare parts+ (or the non-plus version) from the Market. After a period of inactivity and no deep sleep, open the app and tap Battery history. If you get an error, your rom doesn't yet support this feature. The author hopes to fix it soon. I know it doesn't work with my stock, but rooted DX. Change "other usage" to "partial wake usage". Change "since last unplugged" to whatever you want, I use "Total since boot". See what's keeping your device awake. I use this on my Nook Color tablet, which has no dialer installed so when I saw dialer and camera there, I froze them in Titanium backup and saw my deep sleep time climb from 60% to 85%. Spare parts isn't working? Install Watchdog from Market and see what's abusing your battery. I don't recommend using aggressive settings tho. If something is using a lot of cpu, it'll let you know. Once I had email using a lot of cpu, but after rebooting it quieted down. If you have an app using cpu that you don't use, consider uninstalling it or freezing it with Titanium.