Long awaited in the list, voice support for pidgin for GNU/Linux is out, most of them were on Skype all these days for Voice and Video, not any more i feel, with this advancement it's nice to hear and talk also.
Howto install from source:
For Ubuntu user, you may just setup from PPA :
To setup the PPA, copy-and-paste these commands into a terminal:
sudo apt-key adv --recv-keys --keyserver keyserver.ubuntu.com \ 67265eb522bdd6b1c69e66ed7fb8bee0a1f196a8
echo deb http://ppa.launchpad.net/pidgin-developers/ppa/ubuntu \ `lsb_release --short --codename` main | \