Epiphan has a range of devices for screen capture compatible with Quicktime. They work like regular Quicktime input devices, so you can use them with Podcast Capture.

http://Maclearning.org will host a webcast on Quartz Composer Fundamentals and Podcast Producer. The webcast will be presented by Bob Bajwa, Training Development Executive Apple Canada Inc. For more information go to http://maclearning.org/userpage.php?page_id=14

Apple has posted a new version of the Podcast Producer Workflow Tutorial that is now updated for Snow Leopard. It talks a about extending your workflows with custom transitions, compositions, encodings, etc. You can download the PDF from Apple: Podcast Producer Workflow Tutorial

Snow Leopard gives a couple of really nice compositions we can use with our recordings. All these compositions are available when we use Podcast Composer to make workflows. What you maybe don't realize is that using some of these effect might have severe effect on the performance of your workflow. The main culprit is the 'core-edit-master' task.