If you're not familiar with Sonar, it essentially takes data from Twitter, Foursquare, Facebook, and LinkedIn, and shows you people nearby you're friends with or might know. While Sonar isn't the buzziest member of the "people discovery" app category (which includes Highlight and Circle) that heated up at SXSW this year, it might actually be the most capable app of the bunch. Perhaps more importantly, it's trying to solve real problems and not just match you up with other Lost fans at your local Starbucks.

Sonar turned one year old today and launched a few big new features to celebrate. I've been testing the app's new features today, and they make Sonar a pretty compelling experience. The app contains check-in data from Facebook and Twitter, but also adds a couple things neither platform let you do: "Sonar Presence" adds background GPS monitoring which puts it on par with Highlight, while "Sonar Status" lets you ping friends within a certain radius — a feature no other app offers. "We're not trying to be a people discovery app," CEO Brett Martin told me. "Twitter and Facebook are terrible ways to connect with people here now, and that's a problem we're trying to solve," he said.

If you are with a large group of people (like at work), "Sonar Status" lets you ping them all with a message like "who wants to grab drinks in 20 minutes?" without having everybody's number. "Presence" also lets friends see the general area you're in without any check-ins involved. As long as you're friends on one of the social networks Sonar plugs in to, you can connect using the app. "The prospect of a bunch of randoms is not too interesting to people," a Sonar spokesperson told me. The app doesn't pair you up with strangers, but instead tells you when friends or people you might know are near you. If you aren't near any friends, Sonar polls your social networks for how you might know the people who've checked in at the restaurant or park you're in.

So is Sonar finally going to be the geo-aware app you use on a daily basis? It seems like Sonar stands the best chance among its competitors simply because it combines what all the rest do, while connecting you with people you already know. Perhaps the better question to ask, though, is whether the world's ready for a geo-aware discovery app to hit it big.