Under vista, I just create a network folder shortcut to "\\idisk.me.com@ssl\myusername" (replace "myusername" with your mobileme login name). Then, to access idisk, I just open the shortcut.Someone has got to have had some success with the issue of the drive not reconnecting after a reboot.
I haven't found a reliable method under XP. (The above might work for XP, sans SSL, but there's no way I'm going to use an insecure disk.)