Every once in a while I write a scientist/science-like quote on the board & have my students write a response to it. It's very stream-of-conscious, straight-from-the-hip (hmmm... any more cliches in there?!), and they are prepared to share if I call on them.
I was reading the entries from one of my classes today, and one girl opened with these sentences that I absolutely loved:
I don't think knowledge is worthless. I just believe that knowledge without imagination is useless.