Originally Posted by gael33
Is there another SIPS/VoIP program that can be used to speak to someone on Skype?
No. Skype is a proprietary protocol...they've not released an API or other info that would let someone write a third-party tool/plugin to access the Skype network.
Skype is supported under Linux (I use it daily), and works fine for me for both audio-only, and audio-video calls. Skype-Out lets you call regular telephones, too, and also works fine for me under Linux.