How to include pictures in presentations

I've just discovered this article at Microsoft Office. What a treasure trove they have there.

This one, by Robert Lane and Andre Vlcek is called Speaking Visually: Eight Roles Pictures Play in Presentation.

Including pictures in presentations is a simple and powerful way of expanding your expressive potential as a speaker. Pictures communicate at levels beyond the descriptive possibilities of words and bathe the brain in much desired visual stimulation. At the same time, not all pictures are created equally. Choosing the right images, and using them in the right ways, can greatly impact your effectiveness.

... and there are some powerful examples.  This one under the heading "Getting Attention".