I am now the proud owner of one eightieth(-ish) of a supercomputer.
Using the built-in XGrid clustering/distributed computing gee-whizzery in my PowerBook. It took half a minute to offer up all my spare CPU-cycles to the MacResearch OpenMacGrid. A grid that is open for any deserving research number-crunching project. (you can even submit your own suggestions if you are that way inclined.)
This cool widget tells me how much work is being done.
At the moment there are only 80-ish computers on their grid so it’s not that super a computer.. but each new user adds about 1Ghz of power to the cluster.. So joinnn usss.
Alternatively you could join the well established XGrid@Stanford biochemical cluster.