If you have two systems, one of which has HD broadcast monitoring, yes. But I don't think this will help you.
Been looking for screencapture utilities on Linux for years. Never found anything.
You could try ViewletBuilder (it's ported to Linux). Google it, can't remember the company/URL. It records a sequence of images based on your interaction with an application -- you then edit the sequence in a PowerPoint like authoring environment and output a Flash-based presentation that includes an animated cursor that almost makes it look like your actual session.
Don't think it's expensive -- I knkow it's widely used, but it may not be what you need. It can't capture clip playback, for example.