How To Export your Media From Imovie:

• From the Imovie Menu go to Share -> Export Movie.
  

• From The Dialog box choose a location, and set the Size to "Large"

• Your Movie Should now appear in the location you specified(note longer files will take a bit longer to render)

• We now need to convert the movie to an MPEG2 File, to do the we will use a program called ffmpegx, which can be found on the desktop. Go ahead and click on it to open it.

• Drag and drop the movie you exported from Final Cut into FFMPEGX where it says, "Drop File Here"

• Next, In the "Target format" Section, Select the "DVD ffmpeg" option.

• Set your destination in the "Save As" Field, and hit encode.

• You should now have a version of your movie with an mpg extension.