Hi unsungsong,
Welcome to the Q&A Board!
I haven't found any information about using the S3000 as a webcam. It isn't in the specs and I haven't found any reviews mentioning the feature. But I bet someone has figured out a way to do it.
Steve's Digicam has a review of the camera and also has excellent forums. Take a visit there and inquire. I'm sure someone can tell you how to get the camera working as a webcam.
http://www.stevesforums.com/forums/