The terms of service of a website vary from the stupid to the sensible, from short to very lengthy. The Facebook terms, for instance, have been re-worked in an attempt to be plain English and are very wordy indeed -- but not stupid. No, stupid is a website with terms saying "This file may not be downloaded from this site." Imagining (if you have any technical knowledge at all) how someone can come up with that is likely to leave you with a sprained hindbrain. Not recommended.
The FSFE sites have no user agreement (this is something we should fix, actually, since we both provide a service and publish user content). KDE's UserBase has Guidelines and a code of conduct, which don't cover all the bases, but it's a start. Gitorious has something that looks a lot more like traditional terms of service -- one might argue at some point whether not-reading those terms allows one to escape from the choice of venue, in light of the two court decisions listed above.