Skype : Free Internet calls and cheap calls! Skype is a software program that allows users to make telephone calls over the Internet to other Skype users free of charge. Calls to landlines and cell phones can be made for a fee. Additional features include instant messaging, file transfer and video conferencing.

Google Talk : Google's approach to instant communications! Gtalk a great Windows and web-based application for voice over internet (VOIP) and instant messaging, offered by Google. Try it! The first beta version of the program was released in 2005. Instant messaging between the Google Talk servers and its clients uses an open protocol, XMPP, allowing users of other XMPP clients to communicate with Google Talk users.

Windows Live Messenger : Connect, share, and make every conversation count. Windows Live Messenger (formerly MSN/ninemsn Messenger) is the world’s largest instant messaging service. Via instant messaging people can talk to other people who are online at the same time as them, with conversations that happen in real-time.

Yahoo! Messenger : Chat, Instant message, SMS, PC Calls and More. It is a popular advertisement-supported instant messaging client and associated protocol provided by Yahoo!. Yahoo! Messenger is provided free of charge and can be downloaded and used with a generic "Yahoo! ID" which also allows access to other Yahoo! services, such as Yahoo! Mail, where users can be automatically notified when they receive new email. Yahoo! also offers PC-PC, PC-Phone and Phone-to-PC service, file transfers, webcam hosting, text messaging service, and chat rooms in various categories.

ICQ : Community, people search and messaging service! ICQ means "I-seek-you," and it has become one of the world's most popular Internet communications tools. It's free! ICQ lets you communicate directly with any other ICQ user on the Internet, either by direct messaging or in a text-based windowed interface for multiperson chat.

mIRC : An Internet Relay Chat program. mIRC may be the easiest way for a beginner to jump into chatting. It may also be the perfect step up for experienced chatters who are ready for full-featured power chat. You just have to run the installation and open the program to get a list of chat servers worldwide.

Net2Phone : Make phone calls over the Internet. With Net2Phone, you can use your PC equipped with a modem, sound card, speakers, and microphone to talk to anyone, anywhere in the world at reduced rates. It lets you place voice calls while you simultaneously use the Internet. It works through your ISP connection and pumps voice over the same link you use to surf the Net.