VOIP and XMPP jabber client Yate
I tried install ekiga on ubuntu. it was a big fail, no outbound calls were able to be made. could be an issue with iptables or selinux. either way, terminal and apt-get remove ekiga for me.gaggled around and found Yate, it supports voip and xmpp (jabber) for chat.
yate doesn't have much support for video conferencing.
pidgin is my favorite