Linux Portable

I recently moved to Boston for an internship, which could potentially lead to employment in this area. I never understood the huge draw for GPS navigation systems until now. Driving in Boston is one complicated matter. So I've been checking out the current GPS units.

With the transition to summer, I also have more time to devout to a myriad of projects that have been floating around in my head for a while. I've been using Google Groups to organize those thoughts/projects, but I'm not satisfied with it. I want a portable device (like a palm, mid, umpc, etc) that I can use to keep track of all these ideas. Running Linux would be the best.

Now my burning question is, can I combine the two needs? Is there a Linux portable device that can satisfy my two needs?