I think collaboration is a flawed metaphor for getting actual work done, as opposed to the kind of activity people are paid to do in offices.
For the office stuff, a "collaboration tool" like Wave might be a good tool. You can create a hidden conversation and chat with your loser peers about the sociopaths and clueless.
But in my experience, actual work happens almost exclusively offline, intuitively, in the back of the mind, on scraps of paper with coffee or bourbon stains.
Once you get results from that kind of work, you don't want to collaborate, you want to communicate.