CubeTree is a free service designed for companies that would like to build a social network of wikis, shared items, and microblogs for their employees.
Jabbster is a free service that allows families and groups to create private online communication networks.
ShoutEm allows you to make your own public or private network.
Edmodo is a microblogging system designed specifically for teachers and students. Using Edmodo teachers can create a microblogging network for their classes.
I forwarded these recommendations to my colleague and he promised to give some feedback as soon as possible which i will post here.