"EchoLink® software allows licensed Amateur Radio stations to communicate with one another over the Internet, using voice-over-IP (VoIP) technology. The program allows worldwide connections to be made between stations, or from computer to station, greatly enhancing Amateur Radio's communications capabilities. There are more than 130,000 registered users in 150 nations worldwide!"

"OSCAR 51 ("Echo") is a new microsat-class satellite launched by AMSAT-NA, June 29, 2004, (photo on right - click for full size) and became operational on July 30. AO-51 cost $110,000 to launch."