You know, I wonder how practical it would be to have users save all of their important files--Word documents, Excel spreadsheets, tax-related information, resumes, etc--on a thumb drive or remote server. When it comes time to deal with the inevitable build-up of malware and general system crud, nuking from orbit and reinstalling becomes far more viable, as the user's data is on a separate, uninfected drive.
One of the problems with that comes from Windows' applications' tendency to place user files willy-nilly, all over the place. It has gotten much better with XP... but a lot of legacy apps store data in the programs folder, in the HD's root directory, in odd places elsewhere. Backing up completely can be a problem.
I have some Chiropractors whose vertical solution software stores the patient files ONLY in alphabetically named multiple directories (A, B, C, AA, BB, CC, AAA..., etc.) on the C: disk's root directory. The data can't be put anywhere else and work.... but the index to the data is written to the Application's own directory in the Programs directory. If you have a backup of the data but not the index, it is a worthless backup as the software will not re-index it.
Anybody with a library of audio/video files is going to have too much data to put on a thumb drive or upload to a remote server (unless they have a very fast broadband connection). This is a job for an external hard drive.