When computer is left on overnight, the process SpannerAge has a bad memory leak. my uptime is 19 hours right now, and spanner age has taken over 3.6GB RAM. My system has 2.5GB installed real memory, so it's made everything real slow.
Apparently Spanner isn't quite compatible with OSX 10.4....
Spanner
control hot corners; toggle Expose & screensaver
Version: 0.7