I never really got Microsoft's GamerScore on the 360. I mean, I understand it, its just that I don't get why anyone would care. The system seems totally off-balance and pointless. Example, I've logged 5000 hours into FFXI and I have gotten about 30 points. However if i got around to beating PSU's single player (about 12~20 hours) I'd get a nice 1000 points.
Sony currently doesn't have anything like a gamerscore for PS3. Last Thursday they had a firmware update that came with Folding@Home. The project's goal is to use your computer (ps3) to simulate how proteins fold. I admit that I understand very little of how the project works, but the goal of the entire thing is to help cure various diseases. As you run the program it keeps track of your contribution by giving you a score. A nice and more meaningful alternative to the 360's gamerscore.
Anyways, I know a few of the people that read this have PS3s so I'd like to point out that tonight is the first Sunday Night Foldathon. I'll be running mine tonight on my PS3 and I have my pc set to run it constantly when idle. My progress is here (currently 43% through my first unit so probably will be blank til monday around noon), and I have the PS3 at work setup as well which you can track here.