After more than a year in closed beta and amassing over 1 million downloads, Google's Niantic Labs just launched Ingress to the public. What is Ingress, you ask? It's a journey into alternate reality gaming, is one answer. Another answer is that it's a blending of augmented reality with MMO gaming for people with Android devices (iOS support will come later). It gets gamers outdoors in a sort of geo-caching expedition with real-life capture point control.
At present, users can join one of two factions: Enlightened or Resistance. Scattered throughout the game are different color "Portals" to an alternate universe that you can see, discover, and capture with your mobile phone. Agents of the Enlightened want to know more about these Portals and embrace their power, while agents of the Resistance fear they're influencing the way we think (mind hacking) and want to defend and protect what's left of humanity.
This is really just the tip of the iceberg. The game's back story is rather deep and involved, but short and to the point, the world around you is the game. It's a neat way to discover new places and landmarks, and best of all, it's free. If you want to give it a try, you can download Ingress from Google Play.