Those downloaded
Apple Quicktime HD movie trailers can be converted to
MPG4 format & playback in our PS3. It can also convert many other video file formats.
Just follow the below instruction got from AVS forum (thanks to keije)
http://yamb.unite-video.com/download.htmlThen install Yamb (get the second file in there, the one with installer, it comes with everything you need), it's roughly 5mb and is entirely self contained, so it won't affect anything else media related that you have installed. All it is is a gui wrapper for a command line utility called mp4box.
Start Yamb -> Select Creation (on left bar) -> double click "Click to create MP4 file..." -> click Add button to add the trailer you've downloaded then click Browse to select the output destination. Also once you Added the trailer it will show you the streams it contains, you can de-select Video stream, just in case PS3 doesn't want to play Quicktime's brand of h264 (though try not to remove the video first, the trailer is really nice). This is also a nice and quick way of identifying what's inside mp4 and mov files (just for the future, if you don't uninstall Yamb the moment you finish this).
Enjoy