This question was posted in the comments of an earlier post, and I wanted to repost it, and my answer, here for more people to see:
Question for you. I know I could find this out somewhere, but I’m just too damned lazy to check. When you downloaded “Lost” from iTunes, what was the screen size on your laptop? Do you happen to know if the video resizes itself through iTunes down to 320X240?
The video file is 320×240. iTunes will start to play it in the little “artwork” window by default. If you click that, it pops out into its own resizeable window, which you can drag to be whatever size you want.
I was on my T42p, with 1600×1200 resolution, and didn’t want to stretch the video that much, so it was sized to be probably about 800×600. Still very watchable.