Call Me Private - Call Me Private masks your phone number behind a virtual number, for privacy, or for a professional...
Grasshopper - Grasshopper enables entrepreneurs to build a virtual office that connects callers to employees, wherever they are.
MightyCall - Virtual phone system that lets you run your business from anywhere.
Vumber - Toll Free or Local Numbers for Your Business
Truly Wireless - Wireless business phone system built for sales and support team.
Dialpad - Switch is a cloud-based phone system built for Google Apps users.