Here's my setup: I've pretty much turned my laptop into a desktop with this.
Toshiba Satellite A305-S6916
Intel Core 2 Duo T6400 2.00 Ghz
4 GB of RAM
ATI Mobility Radeon HD 3650 w/ 512mb of video memory
Vista Home Premium
I run dual monitors with the laptop screen and the screen above it (I put my twitter, skype, thunderbird, and zune clients there). I run my web browser on the main screen, along with RocketDock. I'm also running multiple desktops, so I can easily switch to my design work when I need to. The monitor next to the laptop is hooked to a computer that I currently don't use. When I move into my dorm in the fall I'll be turning it into a web server so my partner and I can edit files on the same drive, and I'll also be running webcams on it for when I'm away.