In the P2P area with freedom cells, I would also include NextDoor & Meetup (to varying extends depending on your needs and location, but in conjunction with Freedom Cells, it's a good start at least :-)
In the travel section, I would like to point you to the Waze Carpool App, and to a lesser extent Craigslist "ride share" (I've had lots of success there, but it is quite hit or miss depending on where you are).
For the arbitration side of things, I really like the idea of Unitive Justice, though that doesn't really focus on the business side of things more crime/damages.
Somewhat in the arbitration, as well as some of the police-eliminating side of it, I like the idea of Shanti Sena, as put forth by Gandhi and practiced by the Rainbow Family and volunteer organizations worldwide.
I think it would be great if you posted a new version of your open-source list, including whatever else you've learned & discovered since last year :-)