I have been investigating inside the web to find other sites like Twitter but which links are "do-follow" (it gives more relevance to the linked pages on search engines like Google).
I found two: Identi.ca and Tuppy.com. Both work in the same way than Twitter and Facebook: create a profile, for free, and start posting public messages which can contain links, files, and so on.
My main concern was to obtain good backlinks for my blogs. With Identi.ca and Tuppy.com I have been able to do that.
