Freelance/Self-employed project day

Lately I've met a lot of fellow one-man-enterprises who (like me) are curious about the idea of working collaboratively, spreading one's workload and helping to generate opportunity by extending our skill set through the power of a collective... as well as having a semi-permanent group of people to work alongside on a daily basis.

As an initial starting point, I thought that it may be interesting to set up a day where we all get to work on one or more projects together to see whether any bonds are formed which may be string enough to look at the aforementioned idea more seriously.

My initial thoughts would be that we have 4 projects and 20 people. There will be 5 people working on a project at any one time and groups may exchange/rotate members so that everyone gets a chance to work alongside everyone else.

Just food for thought, I'm interested to see if there are any takers for this type of thing and for input into helping to develop the concept further.