Sometimes when you try to access a public folder on someone's iDisk, the iDisk won't show up on the Desktop. All you have to do is logout and log back in and the iDisk will show up.
[Editor's note: Although this has not happened to me, I have heard reports of it from a couple of friends and elsewhere on the web. I would have thought that logging out would have dropped the iDisk connections, but this hint claims otherwise. Can anyone who is experiencing this problem verify the potential fix? Also, is there a command-line method of achieving the same result that would save a logout?]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20020403124435352