The Geekdad blog shares a wonderful idea for a fun activity to do with your geeklet - create a treasure hunt for them - complete with a home made treasure map. There are two lovely examples in the post which draw on local history - one of a pirate treasure hunt, the other steeped in wild west history.
Key ingredients are an old looking map (parchment paper works well, singe the edges with a candle or lighter), an antique-looking chest or box, and some 'treasure' related to the story.
If you want to teach your geekling local history or how to navigate with a compass, this could be a very fun way to do it. :)
Treasure Hunting with Kids [Geekdad]