SIPDroid adds native SIP/VoIP to Android‘s dialer/contacts. Make and receive video calls over Wifi, 3G, and EDGE with perfect voice quality and lowest delay. That’s a good option to access to a VXI* Interactive Voice & Video Response (IVVR) Service.

Video Demo:

Link to Youtube:
http://www.youtube.com/watch?v=PlLZHCHlSY4

More information: http://sipdroid.org