Also for you Nexus One owners that have your devices rooted, there is this AMAZING application call SetCPU (In the market). I have gone from 6 hours of usage to 10 hours just by using this application, no joke.
What it does is allow you to set your processor speed say for example when you reach a certain % of battery or when you are charging the device. The best profile you can set is when the device is locked.
I have it set so my processor goes down to 384 mhz when I have my N1 locked which makes sense because I don't need 1GHZ when I am not using it. And when you unlock the device, I have it set so it goes back to 1GHZ. It really is amazing and makes me love my N1 even more because of this type of customization.
It costs $.99 and is worth every single penny. It even has a little widget and notification bar too. Go get it