You can stream videos, music, pictures, documents, online videos, and more using Orblive. You do not have to install anything on your ps3 to stream files.
1) Download Orblive: http://www.orb.com/en/download_orb
2) Install the setup, and it will automatically send the stream account to any device that is capable of streaming such as a PS3 or even a iPhone.
3) Create an account with Orblive, then sign on at: https://mycast.orb.com/orb/html/login.html
4) Once you are log on, Click on open application and open the video tab. Then go to your My computer and User Document folder, There should be a folder called "My videos, Music, Pictures, and Documents". Put any file there you want to stream to your PS3.
5) Then go to ur PS3 and you will see Orblive. Hit Triangle to view all files and watch your movie.
Note: The orblive icon has to be always be active at your lower right-hand icon tray.