Found a good info of using external USB memory thumbdrive as Windows
Virtual Memory.

From tomshardware.com
”
Adding more memory to your laptop saves power by reducing Windows’
reliance on the virtual memory swap file on your hard disk. In Vista,
plugging in a USB memory stick that you can use for ReadyBoost
(supplementing system memory) can give you longer battery life – we’ve
seen up to 15-20 minutes longer life on a Toshiba tablet PC using a 2GB
USB stick.
”

Now thats another reason for me to try out Vista (minus all the fancy
graphic effects) when it comes out later…