If you don't want to get into kernel changes (undervolting/underclocking), give JD a try. I've been using it for months and found, at least for me, a significant battery power savings using it. Spend the extra couple of bucks and get the JD Ultimate key.. it unlocks a bunch of features. With the same type of use I noticed about a 6 hr gain/day (was getting ~ 14hrs on a charge.. now anywhere from 20-24 hrs). There are many setting combinations, so you'll have to experiment what works best for you. I have it set to turn off the data connection when I'm on WiFi... and when my screen is off, have it set to turn off all radios (and while screen is off, you can set it to ping certain apps like gmail, facebook, etc just for a minute, then turn back off. It automatically will turn data on when you leave your Wifi area. You can also train it to turn on/off certain radios depending on your travels, time of day, use of certain apps, when battery gets to certain levels, etc. It has some cool widgets which show which radios are on/off and can be quickly toggled as well. Anyway, it takes a while to figure out what works best for your situation, but it is very flexible and has tons of features.