There was a kid in my class who brought in one of those 48 hr DVDs. Apparently, when exposed to oxyen, it decays the data and after 48 hrs, the bottom backens and is no longer readable. In theory, if you stick it in a vaccum, you could watch it much longer, but that's not likely. I says it's a stupid idea. Besides, it would ruin renatl comps, who depend on late fees now because of movies on demand. With this, they could go under.