Capture the flag.
A nighttime game of capture the flag is one of the least expensive and most memorable birthday parties for tweens and teens. It gets them outside (and out of your house), uses up plenty of energy, and is a great alternative to dancing and spin-the-bottle for co-ed parties. Just give everyone a flashlight and send them on their way.
So next time you’re trying to decide whether to buy your friend or sister-in-law a Diaper Genie or a swaddling blanket for her baby shower, do neither. Head instead to your local hardware store and get a flashlight … with plenty of batteries.