You can. And now that Google has launched its Google Voice service (google.com/voice), it's free. At press time, the service was invitation-only, but when it becomes more widely available, here's how it will work: You get a new universal phone number with your choice of area code, along with a Web-based inbox to manage your voicemail, text messages and call history. From there, you set up calling rules and filters, allowing you to designate that calls from your spouse, for example, ring on all your numbers at once but that when your chatty cousin calls, only your cell rings or it goes straight to voicemail. You can also listen in as the caller leaves a voicemail or have messages transcribed and sent by e-mail or text, so you can get the gist of the call you just ducked.