What are some alternatives?
When comparing Call Me Private and Google Voice, you can also consider the following products
Grasshopper - Grasshopper enables entrepreneurs to build a virtual office that connects callers to employees, wherever they are.
RingCentral - RingCentral is the leading provider of cloud-based communications and collaboration solutions for small business and enterprise companies
Line2 - Line2 adds a second phone number or complete cloud business phone system to smartphones & computers that's robust yet affordable. Buy online or get a custom quote.
Viber - Free and secure calls and messages to anyone, anywhere. Keep your conversations going no matter where you are.
YouMail - YouMail turns visual voicemail into a personal assistant for handling all your missed calls.
UberConference - UberConference provides a rich visual interface for conference calls. Simple, visual, and free to use, it's audio conferencing done right.