The XMobile project is creating a new laboratory for the study of human behavior. Xmobile harnesses the growing ubiquity of mobile computing for social science, transforming the XLab into a new laboratory, this time “in the wild,” unconstrained by the artificiality of the lab. Xmobile will draw on the Xlab’s subject recruitment, management and payment capabilities. Imagine being able to investigate whether the buying of unhealthy food is impulsive or a well-ingrained habit. As the XMobile subject enters the local Safeway, GPS data streaming from the XMobile application would automatically wake the computational engine and trigger the experiment. The subject’s smart-phone might vibrate and make an offer, or series of offers, proposing differing cash or coupon subsidies or incentives for purchasing healthy vs. unhealthy foods. Researcher and subject will be able to connect in the wild, via XMobile at the real time or place of decision.