Q: "How do I migrate Approval Processes between orgs?"

A: I don't have a really good answer to this question yet. (Better answers are welcome!)

One way of doing it was demonstrated by Red Hat's Chris Mendler at Dreamforce 2009: use a free macro recorder called Selenium to record my configuration actions, then play them back in a different org.

The demo: http://tinyurl.com/SeleniumDemo

The demo slides: http://tinyurl.com/SeleniumDemoSlides