By far my most favorite screen saver, this is the MSaver screen saver for windows. Works great on Windows 2000 and Windows XP and I would guess on other versions as well.
It's written by a friend of mine Antti Kurenniemi who hangs out on the news.barkto.com news server in the nthelp group if you want to contact him.
NOTE version 2.0 is now the download, he has added font and transparency (really cool) support.