Reusable bag? Check. Locally grown produce? Check. Check-in? Check.

Farmers markets nationwide are just the latest addition to the growing roster of places where consumers can “check in” using geolocation technology to support a cause. With an heirloom tomato in one hand and a smartphone in the other, consumers can join Gowalla, Frigidaire and actress Jennifer Garner in the “Make Time for Change” campaign to support Save the Children. For each Gowalla check-in, consumers earn a special farmers market badge, and Frigidaire donates $1 to Save the Children’s CHANGE program to provide food for children in Africa (max donation $40,000).

Tying a donation to a check-in is easily the most common way companies are using geolocation to benefit causes, but the opportunities do not end there. Progressive organizations are experimenting with check-in technology and other new media – from social networks to mobile technology to QR codes – to drive consumer activism and behavior change, too. Exciting innovations are happening every day (such as“5 Mobile Apps Trying To Do Some Social Good”), but the revolution is only beginning. Download Cone’s latest POV, “New Media is Revolutionizing Cause,” to get ready.