Google Voice – FREE!
– Once you sign up (it’s free) you’re assigned a phone number with an area code of your choosing. Calls to this number can be set to reroute to any number of phones, meaning you can have one number that rings your office and your cell. If you don’t pick up, your voicemail is stored online, where’s it’s accessible via any Web browser–or it can be transcribed and emailed to you, forwarded in an email, or embedded in a Website. Other options: blocking numbers, custom voicemail messages for different callers, call recording, SMS voicemail alerts, call merging, and free domestic calling.