Someone told me about this great site today. They have trailers for hundreds of classic movies available for download or just to stream and watch. They also have trailers for current and future movies. I do not know if they have permission to serve all these copyrighted files, but I sure am enjoying it while it lasts. You should probably choose to download and save your favorites, because there's no guarantee that the site will still be up in a month or so, or even tomorrow.
Movie-List - Classics