Not really. Even if you could expect everyone to maintain their own servers (because a phone is not a device suitable for the task) - and remember, we're talking about the general population, not just techies - connecting like this would still be inefficient, compared to a bunch of central CDNs mirroring the data. Also, I can imagine it would be a logistics hell, unless you're willing to add more layers of indirection (e.g. trackers, the torrent kind).