Five Element Arrow Yagi Antenna works great!! I've been able to make contacts in simplex, in excess of 25 miles away.  I've been able to use both digital and analogue modes with repeaters located 25 miles away as well.  I even reflected a single from northeast to southeast to make a contact. I did all of this using only 5 watts of power.  In this video, I am listening to a radio net in digital mode on a repeater that's 25 miles away.  

This is a form of backup communication that's not only parallel to current systems but it's also decentralized.  Simplex communications is radio to radio and it's a really good first line of backup communication.  It can be jammed and direction finding equipment can be used to locate a transmission, but a 70cm signal can be bounced off of hillsides with a Yagi to evade location detection. This particular Yagi can be easily disassembled and carried to another location for use.  Imagine the possibilities....