OK, great! But can you get that into six words?!
Here's a task which (as I had too much material for an hour) I ditched at the last minute from my recent conference talk. It will work well on teacher training courses (there are always lots of teacher trainers at the conference but my focus was on technology, not teacher training).
Define what makes a great teacher… in six words.
I've found this works well in an Edmodo group, in which we began by brainstorming with in fact no mention being made of the six-word limitation, which was brought in at a later stage.
People have come up with lists of nouns, lists of adjectives and lists of professions (teachers are part psychologists, part football coaches…) as well as single coherent phrases (my own suggestion was "generates maximum interaction from minimum material").