As the topic of Interlaced vs Progressive Scans, come up frequently, and often from different directions, I wanted to point to a good discussion of the differences: http://en.wikipedia.org/wiki/Interlaced_video
Also, there are some good examples shown for both Interlaced and Progressive Scan material, and a bit of history.
That Wiki-article might well answer questions that video editor and videographers encounter often.
Hunt
