SIP is the most popular Voice over IP (VoIP) standard. SIP enables two
or more people to make phone calls to each other using the Internet to
carry the call
download free softphone.
http://sipphone.com/softphone/
* It's free!
* Free calls to all Gizmo users.
* Free Voicemail and Conference Calls.
* Super clear call quality.
* Inexpensive add-ons that let you make and receive calls from any
mobile phone or landline.
Area 775
http://www.gizmoproject.com/area775.html
# Free U.S. based telephone number assigned to your computer and any
phone
# Dual Ring - Incoming calls simultaneously ring computer and regular
phone*
Activating Call Out http://www.gizmoproject.com/call-out.html
1¢ Minute Call Out Rate For All US Calls
Call In adds a traditional phone number to your Gizmo, so any phone can
reach you online. Call In numbers are billed in 3 or 12 month
increments for $12 and $35 respectively.