Video courtesy of Google voice
Here’s one of those service options that sounds good but may not be.
Port your existing mobile number to Google Voice (Google Voice Blog)
Assigning your current cell phone number to Google Voice may be desirable to some people. But, it defeats my personal use case: My Google Voice number is my alternate number. It serves as a buffer between the world and any of my phones. I use the plural because Google Voice can ring any or all phones (wireless or wireline associated with it). Assiging my actual cell phone number seems to defeat the purpose, costs me $20, and may create complexities I may not want to deal with later on.