Here's an interesting one, a screenshot from Windows' Disk Management, no more drive letters are available, the partition at the top has no drive letter associated to it!!

There's a 200GB IDE drive, a 160GB SATA drive, another friend's IDE drive, a couple of optical drives (DVDROM & DVDRW), a couple of virtual DVDROM drives, and a couple of USB drives and MP3 players, I thought it'll be fun to see the limit of drive letters in Windows.