1. A method comprising: receiving, at a computing device, a plurality of location identifiers corresponding to a plurality of locations at which a mobile computing device was previously located; defining, by the computing device, a plurality of geographic regions based at least in part on the plurality of location identifiers, wherein each of the plurality of geographic regions defines a physical area in which at least one of the plurality of locations is located; selecting, by the computing device, a subset of the plurality of geographic regions based on respective distances between a current location of the mobile computing device and a respective reference point within each of the geographic regions; and outputting, by the computing device and for display, an indication of the subset of the plurality of geographic regions.