The problem: our school was renovated this year, and our auditorium lost several seats. Combined with a larger-than-normal graduating 8th grade class, we only had room for two guests per student.
The solution: stick a camcorder on the balcony, and run video 150 feet to a projector in the library (aquiring long cables is one of those times where it helps to have a dad who works at a public TV station).
Sound was trickier: to make sure quality was acceptable, we had to get a signal over 400 feet from the soundboard to the library. I was at wit's end, then I remembered Airfoil, a cool little app that can route audio signals over a network. I fed the soundboard into one laptop, put another by the projector in the library, and patched both into our school network. Voila! Instant, perfect audio.
Having a big expense budget is fun, but there's something to be said for problem-solving with limited means. Instead of several hundred dollars in cables or wireless transmitters, I spent $25 on a nifty little shareware app and got comparable results. Go Airfoil!