The basic concept here is that, unbeknownst to many of us, we live our lives surrounded by small treasure caches that have been hidden in unexpected places by people we will never meet. The treasure might be as simple as a coin or a matchbox car, but discovering that it's hidden in the branches of a tree in your favorite park or under the newspaper machine on your street corner makes the whole world feel more magical.

The game has been going on for years, started by a worldwide network of geocachers who stash booty ranging in size from Altoid tins to shoe boxes in locations both remote and urban. Once the the domain of a select few tech nerds with expensive GPS devices, the game is now accessible to most people, via phones with GPS capabilities. Luckily for us newbies, the pioneers of geocaching have already put in several years hiding stuff, so our world is surprisingly replete with treasure just waiting to be found.

The way the game works is that someone – perhaps even you once you get warmed up – hides a box with a memento in it, along with a list for visitors to sign. The coordinates of the hiding place and a clue or two are logged in an online database for others to find. Each person who finds the hidden cache signs the log and is welcome to take the treasure, as long as he replaces it with another comparable item.

What do you need?

One of the most family-friendly features of geocaching is that you need almost nothing. Start by selecting a cache from the online geocaching database; you can do this using a traditional browser, or you can download an app for a smartphone. Free smartphone apps are offered by c:geo and geobeagle for android, or by Seek Cache for iPhone. Other apps are also available, ranging in price from $1 to $15 - including one for $10 on the main geocaching website.

If you're using a smart phone app, you can choose your locations on the go; people going "old school" with a straight GPS device need to write down their coordinates from the geocaching website before leaving home. Either way, the only other thing to bring along on your adventure is some little trinket to replace the one you claim, and a pen or pencil to sign the log in the cache.

Where to look?

Treasures are literally everywhere. We've found them in trees, under lampposts, on street signs - sometimes more than one per city block! It's the perfect activity to cover an hour that you weren't expecting to have to fill. Caches are categorized by size; if you want a bigger adventure, choose a large cache hidden in the hills somewhere and bring a few kids on a hike. Virtually every park in the LA area has something to find.

Once your kids have played a few rounds, they will probably want to try hiding some treasures of their own, and that's fun, too. Once you've signed up for a free account with geocaching.com, your kids can log their own hidden caches and wait to see who finds them. Other players often leave messages that are delivered to your email address; my son takes delight in knowing that other people are out there checking out the tree where his treasure box lies, and he loves getting their messages when they find it.

Of course, while geocaching doesn't necessarily require extra props, there's no need to tell that to the kids. If a wide brimmed hat, a pair of binoculars, or the odd bullwhip takes the adventure up a notch, then obviously that's the way to go. After all, that Indiana Jones theme is a mighty catchy tune.

Photo by Bob n Renee via flickr