No PA at all... I just provide line-outs to each table, and they jack their iPod headphones in. Works just like Bose PAS (everyone in the room gets the same sound) but lots cheaper!

OK, OK, I'm joking!

But wouldn't it be easy... (OK, an FM transmitter for the dancers!)

Every now and again, I get a room where we can't sit in front of the speakers and get a good balance. I'll use a pair of in-ears (I use the nice, inexpensive Sony MDREX51LP earbuds) to monitor the mix. They sound superb!