Iain Sharp transformed his c.1989 Mac SE/30 into a Windows 2000 media server. From Leander Kahney's Wired News article on the heavy-duty hack:
The Mac-ITX is connected to Sharp's TV and stereo, and functions as his DVD player. It runs Windows 2000, and uses Windows Media Player, WinDVD, iTunes and Real Player. Sharp's concoction also features a 40-GB hard drive, slot-loading DVD/CD burner/player, video out (S-video and composite) and USB 2.0 and Firewire ports. It all works by remote control.Link
"With it all crammed together it works like a dream," he reports.