Social network aggregators come and go. There's no end to mobile apps that coral all your friends' posts from Twitter, Facebook and the rest of them. Banjo, which today announced 600,000 active users and a new update to its iOS app, takes a very unique approach to the problem of organizing one's social feeds.

Banjo CEO Damien Patton says the idea for the platform came to him after having missed seeing a friend with whom he'd served in Desert Storm. "He happened to be not only in the same airport as me, but also the same terminal as me for the same two hours of time, and we both posted on different social networks, and it was so frustrating to me that nothing notified me that someone that important was near me," Patton said. 

The service works on a patented algorithm that Patton describes as dropping a pebble in a still pond. "We put you as the rock and we send these rings out in real-time to search the social graph and immediately...we bring back anything of significance or relevance that's happening near you," he said.

Patton says the addition of location information is what allows Banjo to create even more interaction amongst its users.

Perhaps Banjo's strongest asset is that it leverages existing networks. Users don't have to worry about whether their contacts or friends are actually Banjo members for the service to be effective.

"In this new version of Banjo, we've really tried to emphasize this ripple technology, so that when you travel around, or when you're at home, and say an old college friend is nearby, you're going to get a notification that they're in town, regardless of whether they've ever heard of Banjo or not."

This latest version of Banjo, which is available on the App Store for free, includes improved friend alerts and search, as well as integration with Instagram, Foursquare and Gmail.