To access your iDisk on a Windows PC running Internet Explorer 6 (inside a virtual machine, or via Boot Camp), use this web address:
http://idisk.mac.com/username
Enter your username and password when prompted, and you're in!
[robg adds: I can't easily test this, not having IE 6 installed anywhere, but I assume this hint exists because IE6 doesn't like the new http://public.me.com/username pages.]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20090402005522723