That budget could cause some problems if you need an ultra portable w/ 14"+ screen, internal optical and enough horsepower for graphics and image processing. I am not an expert in this field, though, so I'll defer to a few of them...
http://reviews.cnet.com/best-thin-light-laptops/
http://www.forbes.com/2008/06/23/lap...inlaptops.html
http://compreviews.about.com/od/thin...inandLight.htm
http://mobileoffice.about.com/od/lap...inandlight.htm