[wonderwes]

Make sure it has a Pentium M chip, which uses a lot less power on the battery.

The more ram the better, I highly recommend 512mb minimum.

The weight of a laptop will have an affect. You want it to weigh at maximum 6lbs.

Make sure you check the specs of the screen resolution. You want the higest res you can get.

Make sure it has one hell of a warranty.

I bought a dell 600m. It works out very well. When buying a laptop, look for really good coupon codes. I bought my dell when they were running a promo that was posted on gotapex.com. It was $750 off a $1500+ laptop. So I got mine fully loaded with a 4 year warranty, and with the code, a $1600 laptop was only $800. Those codes (most are for Dell's) only come around a few times, so you just have to wait for the right time to get one.