This one's really handy.
First make a directory in /Volumes for the volume you wish to mount, say idisk, for example. You could mount it anywhere, but /Volumes is the logical spot for it:
sudo mkdir /Volumes/idiskthen mount the volume...
sudo mount -t afp afp://user:pass@idisk.mac.com/user /Volumes/idiskThat's it! To unmount, use the umount command:
sudo umount /Volumes/idisk[Editor's note: This can be very useful when you connect remotely and then realize you need to put something on your iDisk.]
Mac OS X Hints
http://hints.macworld.com/article.php?story=2001120201020569