Two interesting Ideas: GFS, is a gmailFS which is a neat idea, but still something that I think violates a person's agreement with google [since I don't see any way it couldn't spider]. A link is here.
The other thing, is that there is this new, in beta, P2P network called Coral . The whole idea is to cache various webpages so that a person never has to a) suffer a slashdot effect b)not be able to find a site. As someone pointed out, it doesn't handle dynamic content so well, but as most of the stuff that I read isn't dyn-generated, I don't care.
Oh and be on the lookout for bookmarklets both the ones listed here and in general. I've got a feeling that this could be something that's going to catch fire.