This device sounds more like a crazy mind control device than a USB dongle, but what do I know. The Black Dog is a self-contained Linux server with biometric security. According to the website:
To access and use your BlackDog, you merely plug it in to your host computer s USB port* and BlackDog takes over! Your host machine s monitor, keyboard, mouse, and Internet connection are taken over by BlackDog for the duration of your session, when you are done, you simply remove BlackDog and everything on the host is returned to its original state.
I'd love to see that in action, just to understand what was going on. Does it give you a Linux desktop? A new UI? Tell me! Tell me!
Product Page [BlackDog]
UPDATE - Wow, an update before I even posted. Reader Phil, whose email I just found, writes:
Basically, it's a usb thumb drive 400MHz PPC Debian box with 256 or 512 MB of flash and biometric authentication, which autoruns an X server on plugging into a PC or Mac, and runs your apps, as well as giving you a terminal to apt-get whatever you want. Best part, it's all open source and completely hackable. Heck, they're having a contest to see who can hack it best.