or, want 1 phone number that a customer can call and can reach you all the time?
Google voice does all of this, is free, and is awesome!
All you need is a gmail address and an existing number to link it to. You can even pick a number that spells something out, like your name.
(android users can link right up to it thru an app, us iPhone users got fucked by Apple but we can still just go to the website and use all the kickass features for free thru safari)