If we look at how people currently share links in social media then url shorterners are very common in use. That would point towards either local or centralized services providing the share-ability of links which would translate between a local address and a global name which may simply be a hash string. There are also QR codes and magnet links which neither rely on a domain name service to operate, but which are used by people to share the address identification for a resource.

They are not trivial solutions to the problem, but the fact that they are in use makes its plausible that a solution can be found.