CuSeeMe ("See You, See Me") is a type of video conferencing over the Net. In addition to software, soundcard and microphone, you need a camera: a Quickcam that plugs into the parallel port is the cheapest, otherwise a home camcorder plus a video capture board. The black and white images are small, but you can get up to 8 users on screen. At least a 28.8K modem and a fairly high spec computer are important. For more details see:

http://www.ambitweb.com/cuseeme/cuseeme.html

NetMeeting (see section 15.7) also supports video conferencing for up to two of the users in the conference (i.e. two people can transmit video, all can receive).