Microsoft NetMeeting is an audio and video conferencing program which also includes chat, file transfer, shared drawing board, and most importantly, program sharing. Program sharing allows you to share a program with other people over the internet -- even if those people don't have that program installed on their computer. It's very simple to use and setup, and best of all, it's FREE.
For more information on NetMeeting ,or to download the latest version, visit: www.microsoft.com/windows/netmeeting.