I am using Imovie 09 with a mac book pro. I am copying video onto imovie and because of size saving onto an external drive. However, when I go to view the movie on the external it is slugglish because of size. Is there a way around this? Also what is the best format for sharing as far as size is concerned. I am the only one viewing the films but the quality has to be good. what do you recommend. I want to view the films on the computer,not iphone or other such device.