P.S.
Got these ideas from one of the parent magazines:
Donut cake - depending where you go, a dozen donuts can run $3-6/dz. Stack them up like a pyramid, fill in a few spots w/donut holes, throw some sprinkles on them and stick the candle's on the top donut. No forks, knives or even plates required - the kids can just grab a donut after the candls are blown out.
Capri Suns - $2 for 10 pouches
Party rings - cut a hole out of a paper plate, take strips of streamers or cut up tissue paper and tape to the back of it and loop through the hole and you have a ring of streamers the kids can run around with.
You could have a karate party...look up some punching and kicking moves online, teach the kids each move. Then have them get up in front of the group one at a time and have them perform their moves by you calling them out and see how well they remember. Totally free!