Nature lovers unite. And next time you’re hiking, don’t forget your iPhone.

Seems a bit counter-intuitive, but if you like Clif Bars on your hikes, and you like free stuff, you’ll want to take your nagging mobile device with you.

The company is launching what it says is the first geo-location Twitter campaign where it will give you free stuff if you send geo-tagged tweets to @CLIFMojoGo next time you’re in a park, at the beach or on a trail. Once they have verified that you are, indeed, outdoors as opposed to watching a nature show while channel surfing or browsing through your favorite story in Outside magazine, they will send you instructions on how to claim your free bar. In addition, Clif will enter you to win a Garmin GPS watch, among other prizes.

According to an article in Mashable, Twitter does allow advertisers to target users in 210 U.S. regions, but does not allow them to target users in specific locations — for example, in parks or at the mall. Clif Bar’s strategy, though labor intensive — they’ll have to verify the location of the tweets manually — works around it.

How is your company integrating clever social media strategies like this one?