For the stated purpose of carrying files (not applications) around, that would not be a hinderance.

Personally, I have a U3 drive, and I do not find much added utility from it. It is kind of cool from a geed perspective, but I have not seen any apps that I can't live without. The things that I have installed are opera and OpenOffice. Every computer already seems to have a browser and office suite, even if it is not your favorite.