The BitTorrent approach seems like a pretty good way of distributing content. To reduce the cost of publishing web content, it'd be nice to make this as transparent as possible, so I'd suggest a local web proxy that used something like BitTorrent to fetch and then distribute requested files -- the important thing being that (unlike Freenet etc.) it'll only distribute files that you've requested, so you're not going to get into trouble for distributing illegal stuff unless you've explicitly gone to look at it.