On Sun, Dec 07, 2014 at 09:34:19PM +1000, Robert Peters wrote:
>...
>are there any usable Skype alternatives?

IHU -- I Hear U -- is an excellent audio-only VOIP system for Linux.

http://ihu.sourceforge.net/

I've been using the "i386 binary linked with static libs" download 
for years on OpenSuse 11.4, and a friend uses it on OpenSuse 13.1.
Both are the 32-bit version of the OS.  He was not successful 
running it on the 64-bit OS, but did not try compiling it from source.

It's very easy to get going, requiring only one port to be opened.
You call a person by specifying their ip-address.  You can do a 
test call by calling your own ip-address, and you should get a 
very rapid echo.

If the loop gain is too high you can get echoes, which of course
can be eliminated if one party uses earphones.  I did not get 
echoes with a friend in Finland (I'm in the US).