foursquare teamed up with (RED) to recognize World AIDS Day Wednesday by allowing users who include #turnRED in their check-ins to unlock a special (RED) badge. From the foursquare Blog:

Today is World AIDS Day. By any measure, AIDS is one of the most dramatic and pressing health issues facing the world today. At foursquare, we like to think that people’s actions can help raise awareness and change behavior, so we teamed up with (RED) to help turn the world red with awareness.

This campaign is even more important because we’re so close: With current treatments, we can virtually eliminate mother-to-child transmission of HIV within five years, creating the world’s first AIDS-free generation. When you shout #turnRED with your check-in and broadcast it to Twitter, it’ll turn your section of the (RED) map a bit more red (and you’ll earn a (RED) badge to help spread awareness further). Hopefully, all together, we can raise awareness for a healthier future.