Volunteered geographic information refers to a range of geo-collaboration projects in which individuals voluntarily collect, maintain, and visualize information. This chapter introduces the related, but distinct, concept of volunteered geographic services (VGS). VGS is based on the organization and exchange of discrete actions through mobile spatially aware devices like smartphones. VGS attempts to extend the limits of VGI by directly linking users together through time and space. VGS’ potential uses in crisis response are considered in light of VGI’s successful role in recent crises. A specific implementation of VGS, created by the PSUmobile.org team, is presented in detail.