Google Voice

Google Voice gives you one phone number for all your phones, voicemail as easy as email, and many calling features for free.

One number for all your calls and SMS
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 as easy as email, with transcripts
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
More cool things you can do with Google Voice
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