eDave was asking how secure Skype really is. Well, the NSA I’m sure can hack the 256-bit encryption, but you have to find the peer-to-peer connection first since there is no centralized server for Skype. There is a nice white paper that covers the technical details in good detail, but in summary, they use digital signatures to make sure that each user is who they say they are. So it is very hard to impersonate and during communications, they encrypt everything with those keys.
Skype also encrypts each communication with a unique AES 256-bit encryption key, meaning each communication will use a different key each time you communicate, making eavesdropping communications almost impossible.