How do you figure out how many GBs you have left on your PS3?

May be...

I've got an 80GB, and I'm a little worried that I'm using too much.

Undetectable is a douche bag. Just go to system settings, then down to system information, and it will show you. You only start our with about 75 because about 5 or so gigs are taken up by updates and system info. Good day.

settings

system settings

system information

that might be a little off but go play around with the options

it doesnt matter ps3 is crap. if you get a 120 gb xbox it tells you how much is left not to mention xbox live and a bigger selection of awesome games