7 here on 2 40GB HD
1st HD 6 partitions:
-Win98 for games not running on Win2k plus Boot files (partition C) FAT32 with NTFS for Win98. All other partitions are NTFS
-Win2K for my kids and other games
-my Win2K main system partition, with internet, Office, audio, graphics progs, etc. (nobody else messes there)
-Win2K just for video editing and ripping
-a separate 1 GB partition just for virtual memory (swap files) of all OSes
-another partition for the storage of all my personal files, documents and stuff I produce, plus downloads, etc
2nd HD
just one big partition for video files, music files, the backups of my system partitions, and just anything else I need to storage somewere
of course I'm in the urgent need to add a 3rd 120 HD for extra junk storage with an extra IDE channels controller card in order to have more IDE channels, if I'm ever gonna get serious about the task of editing my extremely boring family videos and because is just so freaking boring, messy and time consuming to backup to CD's or DVD's