koz

Couple of iPhone apps claim that they can play RMVB files. Such as Movie Player, OPlayer or Azul.  But I found none of them can play RMVB files smoothly.

Those apps are good, but you need to convert RMVB file to MPEG-4 (MP4).  You can just use YouTube Downloader to convert the files.  This is a very good software and it's free.

By doing the above I can guarantee you can play the movie in you iPhone perfectly. As I also have a lot of RMVB movies play in my iPhone.