Startup idea: auto-dropboxify all web/url shared documents, so our downloaded local copies are kept up-to-date with the authoritative copy.<p>A week ago, I downloaded a pdf presentation to be able to open it locally. Today, when I reopened my local copy of the pdf, I wondered if the authoritative copy was changed by the author in the meanwhile. Wouldn't it be nice if my local copy got automatically updated (a la dropbox) if this were the case? This shouldn't be too hard to do. The generalization of this idea is basically an application-level virtual-filesystem that is web-scale.
Interesting concept but my concern would be the frequency of synchronization. Would the service check remote documents (potentially several megs in size) every minute to see if they have changed? every 5 minutes? every 30 seconds? Unless there was some kind of pseudo-dropbox component running on the server where the documents are hosted to alert the service that there is a new version of a document, this doesn't seem viable. I could be wrong though, what approach were you thinking for this?