An interestingly different take here on filesharing.  Not sure how well this would work for non-technical users, but hey-ho.

Another option for file sharing
Posted by Andrew Gerrand, Eric Grosse, Rob Pike, Eduardo Pinheiro and Dave Presotto, Google Software Engineers Existing mechanisms for fil...
Google Online Security BlogAaron Stein
Upspin · Upspin
upspin/upspin
Upspin: A framework for naming everyone’s everything. - upspin/upspin
GitHubupspin