Are you an iPhone or iPod user who use Windows, then ALLConverter To iPhone is a very useful tool. It is a freeware tool which is useful for all iPhone users and it comes with preconfigured profiles for iPhone and iPod which let you choose any video or audio file (e.g. DivX, Xvid, MKV, FLV) and the subtitles file (TXT, SUB, SRT, SMI, MPL2) to make file that would be imported by iTunes on Windows or MAC platform.
The interface is similar to iPhone interface and comes with easy to use functions. The process is extremely fast and you can pause or cancel it, at which time a movie file with subtitles will be created, providing possibilities for part conversion.
There is option to select the quality of video (High or low), there is also a progress bar to monitor the conversions. The application also comes in portable format and you can use it without any installations.