I would be surprised if the hospitals didn't have a rule forbidding plugginy in any USB devices. Most businesseds do because its way to easy for an employee to bring in a virus. Any place that doesn't is just asking for trouble. Thats how most of the virus/worms/etc spread now. Everyone relies on their firewall to protect them from the evil internet but most things come from inside by someone just wanting to edit a document at home. The big news (windows) worms (sql slammer affectinf a bank's atm machines, nimda, code red) all were spread that way.
I know if I were It at a hospital I wouldn't allow anyone to plug in a USB drive from someone unknown.