If you have a minute (literally) you should watch this talk. We talked about Wadsworth Constant. You can remove a great deal of our matter and still make our point stick. The talk below is a great example. Simple message, unexpected using the rocks, and a great story. Also Rosling's is passionate about the subject - that always helps. Could you do this same thing with your Sunday talk? It would make for a very quick - yet sticky - sabha.