Telephony is the technology that is behind making calls from the computer. There are several services that offer this type of technology that can easily be implemented on your own home computer. Two of them that are very comparable when it comes to price as well as service are VoIP and Packet8. Both of these companies are relatively new, as is the technology that allows calls to be made all over the world to landlines, cell phones and other computers all from the use of the internet.