Well, I've recruited all I can that's around me - my own P2-400 and a non-MMX P200 used by the rest of my family (it's installed as a service on that machine - no one knows it's running). I wish I could do more, but I've got limited resources here. But maybe when I get that 486/100 Linux box assembled as a firewall I'll have it cracking in its spare cycles.
So here's my list of tips for those cracking on their personal boxen (not 100% serious, I'm just trying to be funny) to maximize keyrate:
1) If you must play games, play something simple - I recommend Start->Programs->Accessories->Games->Minesweeper.
2) Play your MP3s using Winamp, quarter quality. Sacrifice your sound quality for the benefit of TA!
3) Run Linux. I'm not some open source zealot, but I've noticed that my keyrate under Linux is about 10% higher than in Windows.
4) Get out of the house. Go for a walk. What are you doing here, wasting cycles on a fickin' web browser? Get lost!