Would it be possible for groups.io to have a geo-based businessGreat suggestion. Yahoo Groups started down this path once with the "Groups Labs" features - those were essentially enhanced database tables but one of the available options was a location field, with a corresponding map view of the table.
In Groups.io terms that could be a GeoLocation column type, which if used in a table would enable a map view of the table -- pins for each row, with hover text for each pin showing the other fields.
Yahoo was using their own map product as the basis for the feature, but in Groups.io integrating this with Google maps makes a lot of sense.
This would be useful for groups where people recommendYup.
Another use would be for members to voluntarily indicate their location (as in re-use groups). One of the features of Y!Groups implementation was a control over location precision. It was possible to pin something precisely (such as a storefront or other public location) or loosely (such as "I live in this neighborhood" - without revealing an exact location).
The listings could potentially be linked by admins to the message inOne could use the "Link" column type for that, I think.