If someone really is interested in watching the movie on your computer (in on your iPod or PSP or something since it is downloadable in MP4 format) go right ahead, but be quick about it; it'll probably be taken down once Google finds out about it.
Now, if for some reason someone has problems playing MP4s on their computer (no, I'm not saying this video, it's an illegal copy remember), but would still like to watch MP4s, there is a super player out there that plays everything... seriously, everything. It's called VLC Media Player and it's part of the VideoLAN project, a completely open source project that thinks proprietary video and audio files are stupid ideas. They're open source so they want you to download their product for free and use it, use it, use it.
*Update: Apparently, this is all perfectly legal to have up online. For some reason it's allowed to be circulating the internet, some big sites have it on their pages. Now, it's still illegal to download it, but with a lot of the nice computers out there, it's not too bad to watch a movie online anymore.