Movies2iPhone is an excellent video conversion tool that can be used to convert pretty much any video file so that you can play it on your iPhone, iPod Touch, or even iPad. It is based on FFMPEG, an open-source encoder/decoder that has excellent format support, and it is optimized to allow for great conversion speeds.
Every once in a while, I stumble upon an application that is absolutely great, and couldn't possibly get any better. Movies2iPhone is one of those. It has a very simple user interface that even my grandmother could use. It is as simple as loading a file or files that you want to convert and clicking on "Convert". Also, you can change the folder where you want to save your converted movie; and if you click on "Options" you will be able to select what device you want the movie to be optimized for.
Since the application uses FFMPEG, it can also hard-code subtitles into your files, which is great, since iOS devices don't support SRT files. All you need to do is copy the subtitle file to the same folder as your video and make sure that their names are identical. The app will take care of the rest.
In my testing, I converted a 20-minute video file, with a size of 140 megabytes, and chose iPad 2 as output. The process took a little under 7 minutes, which isn't bad at all. The resulting file looked great, and it even had subtitles.