I mean, if it was a really poular feature of a site you'd want to build it right into the forum. Just make a section under the profile where you choose the winners for the game (poll style), set a cut off for submission/changes - and then post results in a new sub-forum with either peoples win %'s or something like that.
Pools would of course be set up by individuals for the group or individuals.
Otherwise, what does anyone get out of this thread?