[stoney]

Interesting idea, but I wonder how many copies of my data would need to be stored across the system to guarantee that at least one copy is available when I want it?

Many people don't leave their personal computers switched on all the time, especially if they go away for a few days, then there are network outages, people deciding to leave the network, ...

[thaumaturgy]

Yeah. I think some of that would resolve itself as the network grew. Otherwise, whenever I've spent much time thinking about it, I've figured that it should be possible to have a nearest-neighbor node notification protocol.

Node A declares that it's quitting to Nodes B and C (or Nodes B and C are suddenly no longer able to poll Node A); Nodes B and C both check the chunks that they know Node A had, and see if there are enough redundant copies of those chunks in the network.

There's a lot of "and then magic happens!" in this idea, but I'm pretty sure it's do-able. The worst part of it by far is doing node searches on a completely decentralized structure.

[mikeknoop]

You could always run a CDN to add your own guarenteed-up nodes for this scenario.