I'd get a Dell XPS M1330. Nice, tiny little thing with great performance and a really nice screen.
Actually if you research the XPS M1330 you'll find it has a lot of issues with overheating, screen flaws, build problems (chassis falling apart), etc. I wouldn't recommend it to anybody.
If you want to get something light, portable, yet reasonably powerful, I'd recommend you take a look at Sony's Vaio SZ, SR, and Z models. I have the SZ and it's basically the same as the Dell m1330 except it's .3 pounds lighter, has twice the battery life, has a superior screen, superior build quality (carbon fiber), etc., and you can get one for about the same price as the m1330 (although the m1330 can be configured lower and reaches a lower bottom price). The Sony SZ is without a doubt the best lap top computer I've ever owned.