Via Stefano Demiliani WeBlog:

I've just downloaded this tool, CoLinux, a port of the Linux kernel that allows it to run cooperatively alongside another operating system on a single machine. With this tool you can run your Linux distributions on Windows 2000/XP without use other commercials tools such as the famous (and very good) as VMware.

This evening (if I've some free time) I'd like to test it with my Debian... I'll report my impressions.

Sounds interesting...