We recently had our daughter's birthday party, and we held it in a public park near our house, where there's an old parks department building. The sun plan was outdoors, but of course it thunderstormed and we didn't have a back-up plan. So we called an audible and asked if we could use the back room in the parks building and they said sure. So we ended up with a bunch of kids running around a dank, old, concrete room (1950's style - mostly unchanged since then), eating pizza and cake and being entertained by a (wonderful, thank god) balloon twister, in the pouring rain. It was dead simple, and cheap. And the kids had a *fabulous* time. Our daughter was thrilled; one of her friends said it was the best party ever. It just goes to show that sometimes, simple is best (or at least, can be great).