posted this on March 31, 2011 12:21 PM
GroupMe's location sharing allows you to show the people in your group where you are. Your location is never shared with other people in the group unless you specifically add it to a message.
You can do that by tapping "add location" when you start typing a message, and choosing where you are. If you haven't done that for the messages you've sent, no location was shared.
Others must also do this for you to see their location.
After you choose your location, it will appear on the 'map' tab of the app for the other people in that specific group for three hours.
If you have Foursquare, you can link your GroupMe account to it and share locations straight from Foursquare to your groups. You can add GroupMe by opening Foursquare->Me->Settings->Add and Manage Connected Apps->select GroupMe. On the web, you can do that here: http://4sq.com/Q7DOxe