I have heard great things about the Alienware laptops...and they come in more than black & grey.

A little pricey, though.
As I type this, I'm on a Dell Inspiron 7500, 512MB RAM, PIII 600MHz, with a crappy 8MB ATI Mobility-P video card. I'm running WindowBlinds, ObjectBar, Iconpackager, ObjectBar, SysMetrix and CursorXP at the same time with a MINOR hit in speed. In fact, it's so minor that I hardly notice it except in Photoshop and Eudora, so I excepted them. I think it's all in how you put the system together, software-wise. Load one thing at a time and check for stability.
I'm rebuilding my AMD Athlon tower...can't wait to see how WB4 performs with a fast machine and a GeForce Ti4600 and a gig of RAM!