Recs.
Updated
Skype is a very popular cross platform freemium voice-over-IP service and instant messaging client.
SpecsUpdate
Pros
Pro You already have it and it works
Skype is already on your computer, so we make the Skype connection first, then the game connection. There are many negative comments, and some people have trouble running games and Skype together (supposedly solved by starting Skype first). Thus far it has worked with no problems.
Pro Well-known
One of the earliest and most well-known voice chat services. Many people already have an account on it and even have it installed. There's a good chance that whoever you're trying to reach has Skype already set up and familiar with it, avoiding the hassle of installing and getting to know new software.
Cons
Con Client for Linux lags way behind Mac and Windows
There is finally a new client for Linux in Alpha which you can download here. It still has beta and then a public launch to go through, while Mac and Windows both have had full clients for years.
Con No way to adjust volume per user
Some users have better or worse mics, and some are at different distances from them. Some users will be louder than others and drown out the quiet ones. Many chat clients allow you to reduce the volume of the loud players, and boost the volume of the quiet ones...however Skype doesn't.
Con Requires both ends to be online (if neither end is using a cloud-enabled device)
Messages are sent and received only when both ends are online, if neither end is using a cloud-enabled device. In this case, if you are online 9-17 and your recipient is online 18-3, messages will never be delivered.
Con Subpar video quality with more than 5 users
Skype has significant problems with multiple users and video quality. Skype recommends that a max of 5 users group chat as video quality is severely affected. Even webcams tested with other chat services showed lower quality when used with Skype.
Recommendations
Comments
Flagged Pros + Cons
Pro Easily connect with others due to how popular the service is
There's a good chance that whoever you're trying to reach has Skype already set up and familiar with it, avoiding the hassle of installing and getting to know new software.