Input the phone number you want to dial in the first field, and the number of the phone you want to use in the other. So, for example, if you want to call your boss from your office phone, you enter your boss's number in the first field, your office number in the second field, and click the "dial" button. Your office phone will ring in a couple of seconds, and, when you pick it up, you'll hear the rings as GrandCentral dials your boss's number.

Vocito is a big step forward for Mac GrandCentral users, and I hope it's a sign of more GrandCentral advances to come soon. I have a wish list of improvements I'd like to see GrandCentral make.

First on the list: More phone numbers. GrandCentral's motto when it first launched was, "One number, for life." But the problem is not that we have too many phone numbers -- the problem is that our phone numbers are attached to specific locations and devices, rather than our roles. Your home number only rings at home, your office number only rings when you're at work, miles away from home, and your mobile number only rings your cell phone.

I want GrandCentral to give me multiple phone numbers. I want one phone number for co-workers, one that the general public can use when they call me on business, another number for general personal calls, one number that I'd just give out to family and close friends, and another number I give out to people when I'm afraid they'll telemarket me. I can choose which phone numbers to answer, and when, based on the role I'm performing at that particular time.

Sure, I can screen calls using Caller ID -- and one nice feature of GrandCentral is that it lets me assign different voicemail greetings to different callers. But that requires some configuration by me. It would be easier if I could just give out different phone numbers to people based on the different roles they play in my life, the same way that I now have one e-mail address for business, and another for personal use.

More items on my GrandCentral wish list:

• Vocito for Windows. I don't use Windows myself, but I understand a few people do.

• Turn Vocito into a full scale GrandCentral client that lets me place calls, take calls, see who's calling, check voicemail, and configure GrandCentral, all without visiting the GrandCentral Web site. Why bother using a phone at all when you're at your desk? Right now, I use SkypeIn to receive calls when I'm at my desk, but that seems like an unnecessary extra link in the chain. Also, SkypeIn is a fee-based service, while GrandCentral is free; I assume GC might start charging at some point, and that would mean I'd be paying twice.

• Full integration with Google Talk and Gmail.

• Improved integration with third-party apps, such as the Mac Address Book to check the ID of incoming calls, and Outlook and Entourage.

• Smartphone clients. The iPhone has GrandDialer (iTunes link), GrandCentral needs support for other phones.

• Clean up the GrandCentral Web site. It's too cluttered.

For more about GrandCentral, check out my review, or watch this entertaining New York Times video from David Pogue. Be prepared to be frustrated, though; like I said, GrandCentral is in closed beta. You can't have it unless you're already a user.

I asked Google when it expects to upgrade GrandCentral, and open it up to the public. A Google spokesperson responded in e-mail: "As you may know, we acquired GrandCentral in the summer of 2007, and since that time, the team has been working on migrating the service over to Google's infrastructure and adding new features. Beyond this, we don't have any specifics to announce at this time." I've checked in with Google every few months since they acquired GrandCentral, and always get a similar answer.

If you want the capabilities of GrandCentral, but don't want to wait until it opens to the public, you have a couple of options.

The SkypeIn service will give you a phone number to receive calls from landlines and cell phones. The phone number has voicemail, and you can forward your calls to a cell phone. SkypeOut lets you make outgoing calls to cell phones and landlines. Both those services are available for a modest fee. And Skype offers free voice and text chat with other users of service.

RingCentral is a VoIP for business service that provides many features of GrandCentral.

How do you juggle multiple phone numbers for work, business, and home? Let us know.