Both children and adults will dig a scavenger hunt! These organized searches can be a fun and competitive way to celebrate a family member's birthday. Simply split everyone into groups and let them name their own teams. Placing a crown on the head of the birthday boy is always fun, and if your party is large enough, creating custom T-shirts ("Mike's 30th Birthday!") can enhance the lighthearted vibe.
Next, distribute a list of items to find around the house or neighborhood (for kids) or out on the town (for adults). Children can hunt for things like candy and dolls, while a more mature crowd could search for a photograph of someone with a mullet or a unibrow. You don't have to actually collect these items; you can take digital photos of the things you find. Whichever team discovers everything on the list and makes it back first wins. Give a prize to the victor, perhaps a gift card or goofy trophy that he'll be allowed to keep until the next year's scavenger hunt.