How many telephone numbers does one person actually need? I ask because I seem to have more than one would think I might need.

Let’s list them: There’s the house number and my office number (both of these are Vonage VoIP numbers), there’s my fax number (also a Vonage line, but if only faxing over VoIP really worked!), and there’s the number for my DSL line (no "naked" DSL out here). So, that’s four. But wait! There’s more! There’s also my cell phone number and my GrandCentral number. That makes six.

If you haven’t checked out Google’s Grand Central you really should. Still in beta (natch), Grand Central gives you a free telephone number, so Google claims, for life. If I sound suspicious it is simply because, should Google decide to axe Grand Central – not totally unlikely if the company can’t make a profit from the service – then there’s a good chance GrandCentral numbers will simply vanish.

And even if that doesn’t happen there’s the issue of number portability – your ability to keep your number as you shift from one provider to another. Portability is still pretty pathetic because, even though it is required by the FCC, it is a total mess, lacking consistency and enforcement (see the Local Number Portability discussion on voip-info.org). A cynical observer might conclude that the FCC’s agenda on this is more aligned with the commercial interests of providers.

Be that as it may . . . GrandCentral is really cool. Calls to your GrandCentral number can be routed to any of your other numbers simultaneously, with optional nighttime exclusion of your home number. You can also configure which phones the caller is routed to based on the caller being recognized by their Automatic Number Identification (ANI).

You also get call screening, where GrandCentral checks the caller’s ANI against your GrandCentral address book. If it is recognized, when the call is forwarded the caller’s name will be shown and announced.

If the ANI isn’t recognized the caller is asked to say his or her name, which is added to the phone book (which, sadly, is not integrated with your Gmail contact list) and when the call is transferred the caller is announced. You can then take the call or send the caller to your GrandCentral voice mail and optionally listen in as the caller leaves a message. You can have voice mail sent to you via e-mail, and you can manage voice mail stored on GrandCentral from a mobile phone.