When you make a movie in imovie and click on the 'Share' button on your option bar and then hit the 'ipod' button. Then it should import the movie to your itunes library. Once you've done that then you go to click on the 'advanced' button in your option bar. When the scroll comes down hit the 'convert selection for ipod/iphone.' To make sure you have the correct movie you right click on the movie and make sure the movie is in .m4v format. That way you can get the movie on your ipod. When you make a movie in imovie and click on the 'Share' button on your option bar and then hit the 'ipod' button. Then it should import the movie to your itunes library.

When you are ready for your Powerpoint presentation then import the movie from itunes in onto the selected slide. Good luck with your presentation!