This is the Windows/PC counter part of this question.
I want to clarify that I am not talking about connecting a VGA monitor to a computer. I'm referring to plugging in a VGA output in to my computer. I want the VGA feed to show up as a video device, so that I can run a projector's feed through UStream and be able to switch between that feed and the camera that I am using. The computer is a Lenovo Thinkpad.
What hardware is needed to digitize a VGA input in real time to send for broadcast?