So far I haven’t had a lot of success getting USB devices working under VirtualBox with XP as the guest. Perhaps it has something to do with Vista being my host?
I’ve been testing using some USB keys, and while VirtualBox seems to know they are present, the message never seems to make it into my guest OS of XP. I intend to keep working with it, USB support would be one of the most compelling things to make me start using VirtualBox as my primary virtualization platform. However, as of right now USB support doesn’t seem quite up to prime time.