Im on a trip with my iPod touch and I have about 2 GB to spare, but I don't have any tv shows or movies on it, and so I'm thinking about renting a movie. But, on the mobile iTunes store, it doesn't say the memory the movies take up, so I don't want to be stuck with a movie that I payed for but can't watch. If I bought a movie that took up too much space, will the movie get purchased and not be playable, or will the transaction be cancelled altogether? I'm also not sure if the HD and SD will both download, or which one if not both. Thanks for the help!