Geographic location data is sent from a first device to a second device with a modified message to signal the presence of geographic location data associated with the message. The message can include (or attach) the geographic location data or file, or the message can include a link to a network-based resource which the second device can use to obtain the geographic location data. In some implementations, when a user of the first device views a location on a map display of the first device, a graphical user interface is presented to allow the user to select an option to share the geographic location with the second device. The second device receives geographic location data or a link from the first device which can trigger a map display on the second device showing the location of the first device and, optionally, the location of the second device.