Try Juice Defender - has more than doubled my battery life
After the first few days with the Verizon Galaxy Nexus, I was seeing 5-6 hours of battery life. I was seriously considering returning the phone, or at least exchanging it for another one thinking I might have a faulty unit. In my attempt to try anything and everything to improve the battery life, I installed and enabled the free version of Juice Defender. My battery is now lasting 15-20 hours with my 'normal' use which does consist of around 2-3 hours of screen on time. A normal day for me includes reading RSS feeds, web browsing, Facebook, Twitter, texting, email and more. I don't stream a lot of video or anything like that, that would of course kill the battery much quicker. Anyway, with 15-20 hours, I can usually expect to do just fine as I'm never too far from a charger, but 5-6 hours was unmanageable for me.