Stripped down collaborative storytelling.
A VAGUE IDEA
36 cards. One of the 36 Dramatic Situations on each, along with a minimal 'cast list'.

A system to give traits to a character.

A resolution or narrative control system of some sort.

???

Profit.

Edit: I seem to be drawing a distinction in my head between once-off (short-form) and campaign (long-form) rpgs, and how they really absolutely have to be treated as different types of game. A lot of this is stemming from games played at Ubercon this weekend. Best Friends is clearly a once-off game - you're not going to play for more than four or five sessions at the absolute limit with the same characters. I suspect Dust Devils is the same (at least, I'd play it that way). Something like D&D is the opposite, obviously, where long-term character development and advancement is paramount.

Related thoughts:
1) Short-form games should have definite end conditions, and even victory conditions to be meaningful.
2) YPPIDE is a short-form game. I'll need to work on the end-game stuff.
3) Episodic games fall between the short and long-form games. You can convert a short-form game into an episodic game; you can also force a long-form game into an episodic one. The latter is more painful than the former. A dedicated episodic game could be a lot of fun.
4) All these thoughts really warrant full posts, but I really should get The Sweep of Unhistory done first, not to mention my accounts for this year.
5) For fuck's sake, Gar, play more games. That was a really useful weekend there, in terms of new ideas for rpg stuff.