The question is how do we incentivize politicians to start using this. This will not gain any traction if meetings and discussions are held in secret (like ACTA).

Maybe as a start, we can just track what has changed throughout the different revisions of ACTA. Maybe this is something you could do as part of your hackathon.

I'm picking ACTA as it's something that is relatively current and at the forefront of people's minds right now.

One way is to push it through something like Code For America who could then bring it to interested city governments.

http://codeforamerica.org/