Not sure what SIP is.. but Skype is quite nice for voip stuff?
*goes to look up SIP*
Edity: So after a very brief search I find it's to do with mobile communications. Hum. although the Skype site does say:
"Skype is jam-packed with great features to help you stay in touch with friends, family and co-workers, share your thoughts and views and find the information you need. You can use it on your computer and on both WiFi and cordless phones."
no subject
*goes to look up SIP*
Edity: So after a very brief search I find it's to do with mobile communications. Hum. although the Skype site does say:
"Skype is jam-packed with great features to help you stay in touch with friends, family and co-workers, share your thoughts and views and find the information you need. You can use it on your computer and on both WiFi and cordless phones."
So it might still be useful