I'm going to go ahead and try to sell a professional service here to see if anyone bites.
During my day job I manage a team that does event promotion and field marketing work. This is a high impact form of marketing that involves branding the team and getting them out into the world to increase exposure of the brand in question. Typically we have handouts, freebies, coupons, and the like to engage the public.
You, the client, can choose the size of the team and what their materials will be. I currently have 6 outgoing and attractive staff members and can scale up to a dozen with very little notice. For reporting back the results we typically create a spreadsheet with the number of approaches, impressions, and completions we make. At an additional cost we log demographic data as well as preform approach qualifications (confirming age, sex, etc before making the impression).
I think it might be possible to use BTC to purchase all of the materials that might be needed. With shirts, printing, and the like it's really possible to run most of an op off BTC.
It takes quite a bit of communication to lay out the details of pricing, reporting, and conditions that make the campaign a success; and if you are interested I'd like to speak with you about it! I currently have a team in Atlanta, but I would completely consider a Tour Operation that would involved loading the team up to hit numerous locations.
Another branch of this kind of work is Field Usability Studies. In these tests we put a mobile app or webpage in front of users and record how they interact with it. These tests provide INVALUABLE information about how users interact with, or fail to interact with, mobile pages. These campaigns are even more complicated but to someone who needs them, worth every dime.