If you're hosting a big holiday bash for friends and family, consider hiring a clown to entertain the kids at a special "subparty." This way the kids will be out from underfoot, and they can enjoy the things they want to see and do while the grownups do boring adult things.
Remember that clowns usually hire out for a specific amount of time, and they often know to the minute how long it takes to do their program. Few clowns will hire out for less than an hour, so be sure you schedule them for at least that long. Some might even need longer.