I would like to create a program that take pictures programmatically. The ideal setup would be to be able to see on a computer screen how the photograph would be before to take it. Therefore I need to use it as a kind of webcam, i.e. to get the video stream from the device and display it. I have a Canon 350D (and also a Canon Ixus 100 IS) to get the job done. I'm ok using any hacks or SDK to take control over it.