Just before I start, I literally had no idea where to put this. I eventually narrowed it down to here or the community news forum. If it's in the wrong place, that's why.
So, did the old 'clave have any sort of play-by-post game going on? Does the current Conclave have one that I haven't found? If not, might I suggest one, or at least a thread to gauge interest (which might as well be this one, I guess)?
Basically, play-by-post is an RPG that's played on a forum or board. Simple as that, although there generally needs to be some consensus regarding what medium dice rolls take, minimum posting frequency, etc.
Those who also play DnD or like humerous webcomics may know of the GiantITP forum, which utilises PbP games a lot, but for those that don't, I enclose a useful hyperlink:
Guide to Play by Post games.