I got HP ProBook 4410s from my new office and running Ubuntu 9.04 Live CD on it. To test whether the built-in webcam was working I opened a Terminal and typed:
A GUI window with title 'Multimedia System Selector' opened in front of me. I clicked on video tab and clicked on Test under Default Input.
The webcam indicator showed light and I could see my image in front of me. I could take a screenshot of the image.