I have been using various forms of OtR (Off-the-Record: http://en.wikipedia.org/wiki/Off-the-Record_Messaging)
over the years. OtR implementations are not very user-friendly and sharing your fingerprints/identity across different devices hasn't ever been straightforward. Tox (http://tox.im) aims
to solve many of these issues in order to provide a semi-anonymous and encrypted messaging system that is very similar to Skype - supporting encrypted voice, video, and text.
There are clients for all major OS including mobile devices. (https://wiki.tox.im/Client)