Hey San Jose Mommy. I'm a San Jose Grandpa!
I have seen this "graphic design laptop" question many times on Yahoo Answers, and I consistantly respond that there ARE no good laptops for this purposes. Mainly, it is an issue with the size of the monitor, which makes good design paifully difficult. Unless you are designing a final product that is smaller than your monitor, it is hard to work to such a small surface. It is true, that not all graphic design projects are even as small as the largest monitor, but it is simply human nature to do artwork on as large a surface as possible.
All right. Having said this, and, with the recognition that many people, particulary design students, don't really have the option of running both a desktop design station, AND having to carry a laptop for school, the only advice I can offer is that you make sure that the portable system has the most ram, fastest processor and largest hard drive you can afford. Graphics apps keep growing and get more resource hungry with every upgrade. So, get as much raw power as you can, now, to minimize the chance of going obsolete too soon.
Stick with the name brands and, run the same platform as the system at home. I won't get into the Mac vs. PC argument, except to say that I run both types in my studio. THEY WORK THE SAME! But, keep your desktop and your laptop using the same, basic platform. It will make sharing files and peripherals much easier.
Stick with the name brands.
P.S. I don't use a laptop exept for journaling while on road trips and to store photos when my flash cards get full.
Is it going to cool of much more this next week? I like warm weather, but I'm looking forward to the autumn colors.