I think it was Jaiku co-founder Jyri Engeström who coined the term social objects. Anyway, the basic idea behind social objects is that for a social network to become successful there needs to be one or more objects which mediate the communications and relations between people. Social networks obviously connect people, but they need some some remainder of the real to get those connections going and make them valuable for the users.
The fundamental data types have been used soon: Flickr connects people via photos, YouTube connects people via videos, del.icio.us connects people via bookmarks, last.fm connects people via music, Upcoming connects people via events, the Wikipedia connects people via encyclopedic information and so on. But there are many tinier social objects which have been untapped so far in the social network space and which might become powerful mediators, because people attach a lot of meaning to them. Like memories.
Cologne based Memoloop [was http://www.memoloop.de/] is a new site which connects people based on shared memories. It lets you create memos – text, photos, drawings or videos of your memories. Each memo needs to be annotated by a timestamp and geographically.
Memoloop then lets you find and contact other users who have similar memories / created memos which happened at the same time or location. In a way it lets you connect with people you could have met. You also can search for memories or browse memories by location or time.
(This article originally was written for blognation Germany. Since blognation is gone I have reposted it here)