Mitel - Business Communications and Collaboration
Google Voice - Google Voice gives you one number for all your phones, voicemail organized in an email format, free...
Phonebooth - Phonebooth is one of the leading voip providers, providing phone systems & phone service for small businesses.
VoIP.ms - VoIP.ms is a VoIP origination and termination tool.
XO Hosted PBX - Hosted PBX is a scalable UC solution that uses cloud technology to integrate HD voice & data services, mobility, along with advanced calling
VoipSwitch - VoipSwitch provides complete VoIP and unified communications solutions.