Snaptivity is a free Android app which allows you to share photos based on your location.
Take a picture of a group of friends, for instance, and you're asked if it should be public or private. Opt for public and it's immediately shared with everyone in the photo, optionally including strangers in the immediate area (it helps if they have the app, although you can share to Facebook, too).
If the app takes off then you'll be able to explore other people's photos, too. Launching the app displays new photos of your location, if there are any. Or you can search by time or location, perhaps to see if you can find yourself in a photo.
Snaptivity has the usual social networking features: you're able to create a profile for yourself, like or follow others if you'd like to keep in touch.
There's at least the chance of location-based ads, too, which could be either annoying or useful (or maybe both).
There are already a vast number of ways to share photos - sometimes including a location element - and we're not sure whether the world really needs another. Still, it's a neat concept, and Snaptivity might be worth a try if you can get a group of friends to install it.