Each player in the group writes down a memory for the group to act out, three items that have to make an appearance, three words that have to be said, and a location where the memory took place.
Then everyone (including the GM) rolls a d12. The highest three numbers are the people who will act out the memory in question. The players are then given the scene, and relate the tale of what happened based on the hints, words and location given.
For added complexity, each player can be told to bring a prop, and the props distributed randomly for each memory.
Inspired by the improv game "Ask For"