The kids and I watched a great John Piper message from Romans 15 this morning on Lightsource.com. It's called, Holy Ambition: To Preach Where Christ Has Not Been Named. If you have time, I highly suggest watching it. He even addresses part of the message to kids, so if you have kids you think would benefit from a good "word" from Piper, have them watch it, too. (His Piper-style delivery always engages my kids!)
It's an excellent, excellent message.