rallyAll over the social Web these days, there’s a race to get as many friends, followers, readers, or subscribers as possible—most of them people you don’t know. As location-based social applications like Foursquare and Gowalla grow, they’re broadcasting your location to all those people, connecting you in one more way to a lot of people you’ve never heard of. As our “circle of friends” grows out of control, we wind up more public than we mean to be, sharing information with everyone just to be able to share it with our real friends.

New location app rallyRally is different, though. There’s no way to add Rally friends from Twitter or Facebook or anywhere else, because as Rally sees it, those aren’t really your friends. The only way to find someone on Rally is to look for them, which seems to be an effective way of narrowing the scope down to people you know. By intentionally stripping down the friend graph, and making friends come only from Rally, real friends can keep up with each other and keep everyone else out.

Other than that, Rally works a lot like Foursquare or Gowalla, letting you check in at a given location (restaurant, movies, etc) so your friends know where you are—you can even include a picture with your check-in information.

If you see a friend is somewhere, you can click “I’m on the way,” and let them know you’re coming to hang out. There’s also a bit of the game aspect, with users able to earn badges and the like–even more badges than Foursquare, potentially.

While Foursquare and Gowalla could be used the same way as Rally (letting you select friends one at a time), they’re integrated with Twitter and Facebook and encourage you to push all your location data into your other networks. So Rally’s not the only application that can restrict who gets your information, it’s the only one that doesn’t give you another option. The intent of Rally, more than the uniqueness of the use case, is what makes Rally notable.

Forcing users to rebuild their friend graph is a risky maneuver, and it remains to be seen if Rally can work on a large scale and do well enough to convince people to seek out all their friends on the service. It’ll be interesting to watch the company over the next few months to see how it fares.

Rally’s business plan is simple, as co-founder Sol Lipman told TechCrunch: using location to serve advertising. The potential with location-based ads is huge—you could walk by a store and find its coupons for the day, or see the happy hour specials at every bar within a six-block radius of you. Foursquare and other companies are making these kinds of deals, and Foursquare has already raised $1.35 million to extend into 100 cities, while Gowalla’s already got $10.3 million in the bank.

For right now, Rally is iPhone-only (available in the App Store), and is only usable for those in Santa Cruz, Calif. But the company says it’s going to be expanding both platform and location availability.

Rally is based in Santa Cruz. Many members of the startup team were on the team that created 12seconds, a short-form, video-based social network.