The battery life seems to scale with usage drastically.
I typically get around 4hrs, but have gotten 5+ with bluetooth and wireless turned off and the screen dimmed a bit while taking notes.
Definetly keep the bluetooth and wireless turned off when you don't need them and dim the screen as possible. Don't keep a USB flash drive plugged in, mine seems to suck my battery.
MacBook 2.0CD, 2GB RAM, 10.5.8
[SIZE="3"]Apple's handling of iPhone apps is quickly souring my taste for apple products. I've aquired a Windows 7 machine instead of the new MacBook as my form of protest[/SIZE]