Since I started to use a Windows Vista laptop as my "set top box" to watch Netflix movies, the Mac mini I used to connect to my television is now idle. The laptop has a broken LCD screen and has an S-Video out so it makes a perfect TV system.
The Mac mini however is a nice little machine. I'm excited to get it going again - I've planned some silly ideas - like installing OpenSolaris on it, but now that Oracle bought Sun, I'm a little wary about investing too much time into OpenSolaris until Oracle figures out what to do with it. Sure its open source, but its still very much tied to Sun's hardware offerings.
I've also thought about installing PureDarwin on it, but its not really there yet. Like Minix or the Hurd, for me its best kept to virtual machines.
I may stick with Mac OS X 10.4 and mess around with MacPorts and Fink until 10.6 comes out. Snow Leapord looks really nice!