I love the idea of a playmofriends calendar... my only suggestion would be for one of the guidelines for each month's submissions to be that they try to be appropriate to that month. I.e. no eskimo pics in July...
Also, if we really plan on making a printed calendar, we probably ought to establish guidelines for the size of the pics needed/their resolution, etc. Otherwise the pics may look great online, but terrible on paper at the size they will presumably all be blown up to.
Cheers,
Red