I have a friend looking for a solution to a problem. The problem is: there is a group of 200 or so people, all of which should be able to see each other's contact details (on the web / on mobile devices). The people should be able to edit thier own information (or an admin could do it). The information should only be accessible by the group of people.

The service should only provide the contact details, not provide other tools such as letting one user email another (that would be done by the user once they've got the recipient's address from the system). No need for photo sharing or the like.

Oh, and my friend is price-sensitive too, so a free option would be best.

Do you have any ideas about such a service? Is there one?