Google is launching it's another rocking service very soon... This service is for people who maintain who maintain multiple phone numbers — home, work, mobile, etc. ..Google Voice is currently available for GrandCentral users only(The new service is actually the newest version of a company they acquired called Grand Central ), but will be open to googlemail users soon.
The idea is that you get your own “Google Number” in an area code of your choice, and you let Google route all your incoming phone calls to every phone number you have.
The new service has all the features of Grand Central, so you can do some pretty cool things like answer a call on your home-phone, and during the call, you can pick up the same line on your cell phone — handy if you’re just about to leave the house. Here’s a more detailed list of the features you can expect to find in Google Voice:
- Call screening - Announce and screen callers
- Listen in - Listen before taking a call
- Block calls - Keep unwanted callers at bay
- SMS - Send, receive, and store SMS
- Place calls - Call US numbers for free
- Taking calls - Answer on any of your phones
- Phone routing - Phones ring based on who calls
- Forwarding phones - Add phones and decide which ring
- Voicemail transcripts - Read what your voicemail says
- Listen to voicemail - Check online or from your phone
- Notifications - Receive voicemails via email or SMS
- Personalize greeting - Vary greetings by caller
- Share voicemail - Forward or download voicemails
- Conference calling - Join people into a single call
- Call record - Record calls and store them online
- Call switch - Switch phones during a call
- Mobile site - View your inbox from your mobile
- GOOG-411 - Check directory assistance
- Manage groups - Set preferences by group
Try this link ..How it works