On my shelf at school is a big inflatable die, it takes pride of place and whenever I walk towards that area of my classroom my pupils eyes widen in anticipation; for this is a special die, the die of Ultimate Power!
The die is my favourite plenary, and the kids love it too. The crux of the idea is that the pupils throw the die to each other, and whichever number they catch it on they have to contribute in a certain way. Of course people can pick any 6 options at this point, but the ones I use are:
1) Give a key word used in the lesson.
2) Summarise a key point of the lesson.
3) Explain a key idea from the lesson (and I insist on full explanations).
4) Give me something you don't understand following this lesson.
5) Give me something you would like to find out following this lesson.
6) Free choice from 1 to 5.
If the pupil gives a suitable response, they get to line up by the door ready to go; if they don't or they don't pass it on sensibly (stops them trying to bat it around or throw it forcefully at someones head) then they have to sit down. The lined up people get to leave first, then anyone that is still stood up (I have them stood behind chairs so I can see who hasn't had the die yet) gets to leave, then the people who have sat down leave last. Pupils either really want the die, or have that 'I don't want it' but smile when they get it. You get some really quality feedback and the idea can be adapted to question difficulty selection or a whole host of other things (not to mention having a big die in your room just tends to come in handy; I used it for demonstrating mutual exclusivity the other day by asking a pupil to put the die on the table so both the 5 and the 2 were visible).
Must give a nod at this point to Jamie Butler at Oxford Spires Academy who originally gave me the idea.