The new laptops from AMD (Turion) have very impressive battery life.
My Dad bought this laptop about 3 months ago, and it has about 4-hour battery life, with constant use (played games on a road trip).
The video card on it isn't impressive, but it's large (17"), and 1GB of RAM. All under $1200.
The core 2 duo's are powerful, but I was told at Future Shop that they only get about 1.5-2 hours with that processor. And they're called Centrino Duo with laptops.