I was look at NoseRub,but it like StatusNet is the open source micro messaging platform that helps you share and connect in real-time within your own domain.
http://status.net
That sounded like a advert Gpo1. 
The noiserub-protokol is very simular to the open stack. So you can built decentralised networks. It would be very nice to have support for is in Buddypress.
Applications with the NoseRub protocol keep information about profile data for each of the contacts. These profiles get synchronised between the applications/social networks … and can be used by any other NoseRub service. NoseRub uses already available standards like OpenID, RSS and FOAF to provide the goal of having a truely decentralised social network.
Gotta tell you though… NOSERUB has the WORST Installation process… just terrible…
It would be cool. If my users just sign up on my buddypress+WPMU+NoseRub install and there profiles get the benefit of “aggregated” content..
But Frankly, theres a lot of duplication in feature set…
…though.. it would be cool…
@andy,
lol.. no advert, but I’ve got a site that runs it, API same as twitter maybe it could be adapted!
I just checked out Status.net it looks very mature and full featured.. too bad though that the requirements are pretty steep.. I hate upgrading my PHP
