We were coming back from some convention or other in the car and we wanted to roleplay. The dice were packed away, but someone had some Opal Fruit sweets (since renamed "Starburst"). The system was that when someone wanted to do something, a sweet was pulled from the bag. Depending on the colour/flavour, the results were something like this:
Yellow/Lemon = Failed miserably
Green/Lime = Failed, but only just
Orange/Orange = Succeeded, but narrowly
Red/Stawberry = Excellent success
I think we were playing Cthulhu. Character names had to be based on the roadsigns we saw from the car or from the AA roadbook we had in the car - so they tended to be things like Dr Ernest Kidlington (a place near Oxford) and Captain Heath Flackwell (Flackwell Heath, just outside London).
Oh, by the way, you also had to eat the sweet, so there was a natural time limit for solving the case - when the sweets run out! No sweets left = no chance of success = oh dear, killed by Cthulhu's minions.