Another option is to export still files out of Power Point, or even better, Keynote. The iWork Suite is sold by Apple for $100 or so I think? And Keynote is worth the price of admission alone. It will auto-resize your slides for proper video dimensions. As a general rule, Power Point’s default slide sizes are not video friendly especially when you consider that Video Safe is the inner 80% of the screen.
So the first step is to really make a slide template to work with FCP’s settings (10×6.66inches for a slide dimension should work with DV size video- 720×480 pixels). Within that template, mark out title safe areas and make sure that all of your text, graphics, etc are inside of title safe, and then the next step would to be to export a movie file or graphics of your slide, then cut in FCP. Either PowerPoint or Keynote can be used, but Keynote has a reputation of being snazzier when it comes to transitions, animations and default tempaltes.