ExtraWebcam is the software that enables you to use Canon PowerShot and EOS series cameras as regular webcams for video conferencing, video recording, remote area monitoring and other webcam tasks.
It supports any Windows software that take a standard video capture source as input such as Skype, MSN, AIM, Yahoo Messenger as well as online services like Ustream, Veetle, YouTube. You only need to select ExtraWebcam video source, connect your camera via USB and power it on, the rest will be done automatically - search for a connected camera and taking control over it.

ExtraWebcam has a tray icon utility that helps you to work with your camera. You have the live viewfinder window there and camera settings controls like shooting mode, shutter, aperture, ISO, white balance, zoom. You can use ExtraWebcam for automatic interval time-lapse shooting, it's possible to record video stream and time-lapse sequences into MJPEG AVI files.

List of supported cameras:
Canon EOS 1000D/1100D/450D/500D/550D/600D/40D/50D/60D/7D/5DM2/1DM4
Canon EOS Rebel XS/XSi/T1i/T2i/T3/T3iCanon PowerShot A60/A70/A75/A80/A85/A95/A300/A310/A400/A510/A520/A620/A640
Canon PowerShot G2/G3/G5/G6/G7/G9/G10
Canon PowerShot Pro1
Canon PowerShot S1 IS/S2 IS/S3 IS/S5 IS
Canon PowerShot S30/S40/S45/S50/S60/S70/S80/S400/S410/S500
Canon PowerShot SD100/SD110
Canon PowerShot SX100 IS/SX110 IS
Canon IXY 200a/300a/320
Canon IXY PS S200/PS S330/PS S230
Canon IXY IXUS v2/IXUS 330/IXUS v3
Canon IXY DIGITAL 400/500
Canon DIGITAL IXUS 400/430/500/II/IIs