I'm mulling over way to make it so that Proof-of-Bandwidth can become a practical means of proof in cryptocoins. Anyone that wants to use my ideas is welcome, but I'd prefer that you involve me in your creation so I can contribute more.
The promise of Proof-of-Bandwidth is two-fold: Bandwidth is more evenly distributed among people than computing power, and unlike work, of which there are many kinds that each can be optimized through specialization, there is one kind of bandwidth, and improving it for Proof-of-Bandwidth will improve bandwidth for other uses.
However, there are pitfalls. First is the problem of auditing; no one wants a bloated blockchain, but you want to make it so no one can just claim that they sent or received some chunk of info. Second, there is the potential for a modified Sibyl attack where a machine can simulate multiple machines inside of it, with predictably high bandwidth between the virtual machines, and pretend like each one has high bandwidth when in fact it's all inside a machine that is poorly connected to the internet.
I'll be detailing what I'm thinking below. Any help is welcome!