You may have noticed how very easy it is, with PowerPoint, to make slide shows that look good. When I did a lengthy presentation for a local nonprofit group, I used a couple of photos on my PowerPoint slides that were there basically because they looked good. Images are especially helpful with long presentations because they provide relief from the monotony of one text slide after another. All I had to do was click on a slide, which let me browse for the photo I'd downloaded, and click Open. The photo would appear in the middle of the slide, where I could move it around or stretch it horizontally or vertically to suit the design. Very easy.
As YouTube demonstrates, it's not so easy to make a video that looks good. This occurred to me when I was thinking about the easiest way to present information via multimedia on a website. If you use Webs.com to design a site, you can put a PowerPoint show there, complete with soundtrack. It will run the show with about 3 seconds for every slide, the final slide shown indefinitely. You can slow it down by putting more than one copy of a slide in the sequence. For the soundtrack, you can use recorded music or a microphone, and any audio file format, so long as you convert the format to mp3. At this time, Switch, a highly-rated conversion software, is offered as a free download for non-commercial purposes.
There are copyright issues that I wasn't worried about for that thing I did for the nonprofit group, but it's no big deal. There's an abundance of public-domain images. (Verify, because copyrighted images don't have to say they are that.) It doesn't take an artistic genius to use a photo as the basis for a drawing, and much of the work can be done by changing the contrast. (Just stretching the image or changing its color isn't original enough.) If by chance you are contacted by the owner of a picture's copyright, in all probability the owner will want payment, not a lawsuit (unless you happen to be, say, Exxon.)
About downloads -- of programs OR data files, such as photos or music -- experts say that it's best to download while your browser is confined to an environment called a sandbox. You can find out at Sandboxie.com.
Another way to publish your slideshow is to make it into a video with software like AVS Video Editor. Then you can post it on YouTube or a website. AVS AUDIO Editor, also used for making videos, is sold separately. My experience with AVS is that the lettering on my slides doesn't quite come out as sharp as I'd like, but photos are reproduced well.