I've got some long running series on YouTube that I enjoy watching, but I have 'viewing gaps'. Example: I started watching This Week in Startups around episode 40, and eventually went back and watched ~ 1-15 (not sure if that's the actual number) I don't always remember to catch it every week. I'm wondering if there's some part of the page I can look at when viewing a video to see that I've viewed it previously (I realize this may be imperfect since the TWI network moved authors when it became a network. but anything is better than nothing).
I'm willing to adopt a slightly different workflow if it helps solve my issue of not knowing whether I've seen an episode of something. (seriously for all the buttons YouTube has ... it won't even display on the video page that I already 'liked' that video)