BlackDog is a great concept. It’s a flash-based Debian Linux machine that fits in the palm of your hand (400Mhz PowerPC and 256 or 512MB RAM), with just a USB 2.0 plug, SPI and MMC Expansion slot, and a thumbprint sensor. There’s no battery or power plug — it’s powered completely via the USB plug.
Plug the Dog into the USB port of a Window-XP and it’ll automatically boot up from ROM in about 2 seconds. Then it claims to be a USB CD-ROM drive with an auto-run program, from which it starts up CygWin and X, and then makes an X connection back to its own server. Presto! Instant use of the host machine’s display and keyboard with your CPU, computing environment and data (up to 1GB through the MMC slot). Unplug and the host machine is left just as you found it. Security comes from what you have (the Dog itself) and who you are (the thumbprint reader), though of course you’re still susceptible to low-level keyboard, screen and network sniffing attacks from the host machine.
There’s a lot we could ask for from a personal server that BlackDog doesn’t have, like automatic wireless sync-up with the interfaces around us, but this sounds pretty decent and more importantly it’ll actually work with today’s infrastructure and machines.
(Thanks to Steve for the link!)