I have an awesome way! I do it all the time through torrent sites. Just download andtorrent from the marketplace to handle the torrents. You may know all about torrents, but for those that dont, simply find the torrent for the movie you want. Search google (ex: district 9 torrent), find the torrent you want. Thepiratebay.org is usually pretty good, but demonoid rules. Andtorrent has a built in search feature as well. As for the format, mp4 is the most widely available compatible format, so i stick with that. Download the torrent file, then in andtorrent add the torrent. Ive gotten some perfect ones, i just downloaded a perfect alice in wonderland screener a few days ago! Good luck, and this isnt the only option, but i prefer it.
