Sometimes, the best things are free.
It’s easier than before but takes a little time. Or for those who don’t have the time,...
LiveUSB with OpenBSD
LiveCD with OpenBSD
Or a commercial service like
TOR is fine as far as it goes, but it relies on existing networks, protocols, and infrastructure. What jimjohn is saying is that a completely separate communication network is needed. One that can’t (easily) be compromised or monitored.