if you join a good clan, they have certain things, thus follows:
money tree: i believe (not 100% sure) this thing gives every clan member some meat every day.
Clan Chest: allows you to donate meat/items or take items from chest (donating meat/items gives "Clan karma" points, and taking items takes awaay karma, thsu karma is basically your clan currensy.
Calander: i think this gives more adventures.
Gym: allows you to work out certain things (muscle/myst/mox) at the expense of adventures (roughly 10 adventures = 100 pts into that area i believe)
and a bunch of other crap i cant remember...