Great ideas sometime come from surprising places.
My 11 year old son, Jonathan, came out of the blue with an idea for retrospectives:
Take a bottle, and put it in the middle of a circle where the team is having their retrospective.
Someone turns the bottle, much like in Truth or Dare.
When the bottle stops, the person the bottle points at answers:
What did I learn? What did I know?
The team does this in turns, until everyone talks.
Use it a a data-gathering technique, and continue with a dot-voting to decide what to do. Or use it as a fun closing technique.
(Some will find it useful to mention here that the bottle should be on the floor, and not, heaven forbid, on a meeting room table. I will spare you the embarrassment and refrain from such silly comments).
Short, sweet and fun!