If you've watched Chris Kubasik's awesome Booth at the End series, I know you'll want an RPG along those lines. Luckily I've written one. It's called Crossroads and has been accepted for the Danish convention Fastaval in April 2012. If you are facilitating it at the convention, you get a free copy from me. If not, you can buy it from Lulu very cheaply
What it really is: it's a story game with predefined characters designed to run in less than two hours. It takes a facilitator and up to four players. It's been playtested like mad and it delivers. Every time.