GrandCentral.com

With GrandCentral, you get:

* All your calls through a single number. Add your other numbers to your GrandCentral account and then make your own rules for how and when your phones ring. Go to the Settings tab and look under Phones to add forwarding numbers and change your settings.
* All your voicemails in one place, saved for as long as you want. If you don’t answer a GrandCentral call, your callers will be sent to your GrandCentral voicemail. You can then check messages by calling your GrandCentral number, by logging into your account, or by checking the GrandCentral notification email.
* Handy features that work the same way across all your phones