I've been searching for awhile for a command line sip phone or sip library. There are some really good c and c++ libraries available. However, it seems the high level scripting world has been left behind (ruby,perl,python,bash).
The best canidate I've found has been linphonec. Has anyone used linphonec for scripting? It would seem overly complicated to do so, but I don't see much other choice. It would probably require expect to manipulate the linphonec console and another thread to manipulate sound.
This would be useful for automated calls. Things like wakeup calls, confirmation with a client before a meeting, use your imagination. Asterisk doesn't seem to have the ability to act as a very scriptable sip client (please correct me if I'm wrong).
I'm sure the combined knowledge of this list could result in enough information for a solution that would be useful for a lot people.