I think my answer is going to be a bit different than others: I probably wouldn't participate in any kind of formal network that involves carrying things for people in exchange for future items, compensation, etc.
If there's an FT'er out there that
I already know reasonably well, even if in a purely virtual sense, I'll fetch that bottle of barbecue sauce or oddball T-shirt for you - no charge. Buy me a beer or something.
But if you're thinking of some sort of new social network / new venture project...maybe it'll work, but I'm unlikely to be an early adopter.
Love the Chipotle burrito idea, but how well do those things travel?

I guess if you're jonesing bad enough it doesn't really matter!