Most of these devices don't actually need drivers for XP as they are built into XP so that in its self would be a major problem.
The only USB Devices that really need drivers are things like Scanners and printers all the USB Thumb Drives or HDD's are [b]Plug & Play[/b] so you would have a problem there. Though if none has ever been fitted to a system maybe with restricted user rights it may be possible to stop the drivers installing, However it's something that I've never tried doing as basically I'm [b]Lazy[/b] and always log on as Admin when I'm working on systems I've never tried plugging in one on a system with restricted rights so I'm not sure how things would go.
I've always used GP's to restrict users being able to use things like Thumb Drives and USB Drives and I've never had a position where the end user has needed to be able to use devices like this that where not given the rights to. Actually for that matter I'm not sure how things like Digital Cameras would go under a GP like the one above as technically it's possible to plug in a Digital Camera and copy data to the Memory Card to walk out with but it's something that I've never actually looked at because it's never been an issue previously.
When I worked Bank Security we locked down every terminal that was used and only allowed them the ability to do one job at the front counter and then others in the main processing area different jobs like to do International Transfers or make up Bank Drafts both International and National. So really it's something that I've never had the need to actually look at generally speaking every USB Port was disabled in BIOS with a Password on it to prevent the users enabling the ports as we didn't actually use them.
All I can suggest is that you try it and see what happens on a work station with restricted rights and see if it allows a Thumb Drive to install itself.
Sorry about that.
Col