I can picture some startup somewhere coming up with a mobile P2P network/overlay that leverages an ad-hoc wifi mesh of some sort (avoiding carrier data limits) that lets users share everything and anything with just a psudonym. Or maybe even just a randomly generated key as a URI (I.E. Tor).
I've yet to see a simple implementation that I can install painlessly that lets me send text, let alone more complex stuff. Any startup that can deliver all that in this surveillance-happy atmosphere will make a killing.
There's a few good open source implementations out there already for phone calls and SMS. The two below were done by Moxie Marlinspike. They're built for Android, but I'm sure they can be ported elsewhere with the source being available.