My original format is Keynote, which has a neat feature that lets you cut shapes out of pictures. Power Point limits you to only rectangular pictures, so the remaining borders obscure other parts of the slide. Since this is a feature I use a lot, the power point versions do not look good -- try a different format. The shockwave version looks pretty good. The PDF version is good for downloading; the HTML version is viewable on-line (please don't link to individual slides, though).