Google’s Ingress

It sounds like another good way to get people to gather data for free.

A Google Surprise — Worldwide Alternative Reality Game Ingress Revealed | Singularity Hub

Google is venturing again into the realm of augmented reality with its reveal of a new mobile game called Ingress. Though the multiplayer game is currently in closed beta, Google has built a marketing campaign around it that entices players who were drawn to TV shows like Fringe and Lost.