Skype
Functionality still varies depending on your Internet connection and what else you're doing with it while using Skype, but they are making some efforts to improve that. When you finish a Skype call, a Web page opens and asks you about the conversation's sound quality. The clean layout combines familiar chat client functions with a dialing interface, so that calling a phone is as simple as entering the desired number and hitting the dial button.
There are also Skypecasts, throwbacks to the party-line multiperson telephone conversations from the mid-20th century. We think Skype is a strong contender in the Internet Telephony category, and anyone who's interested in talking for free should give it a try. For international callers who have computers, this program is a no-brainer solution for long-distance bills.
Version 3.8.0.144 has Firefox Skype plugin updated to version 2.2.0.94.