There are a number of ways to do this.
You could use a program, like GifBuilder (I think that's a Mac product,
but there are many others) to create an animated GIF out of your
pictures.
You could create a series of animations that have pictures coming in and
out. 2002 and 2003 allow a single item to be animated multiple times, so
you could set an entrance effect and an exit effect for each picture and
repeat that as many times as you like.
You could create three identical slides, except that each slide contains
a different picture. You can put these slides in a custom show and set
them to automatically transition after 3 seconds. Create a button that
links to the custom show and check the "Show and Return" button. If you
put the slides in the custom show several times (slide A, slide B, slide
C, slide A, slide B, slide C, slide A, ...), then you can hit Escape to
return to the slide with the button that links to the custom show.
You could put your three identical slides in a separate file and have
that file set to "Loop continuously until Escape" (in the Slide Show menu
under Set Up Show). This works basically the same as the previous
suggestion, except it will keep rotating the slides for as long as you
want (until you hit Escape).
Finally, this can be done with VBA, but given all the easier options
above, VBA is probably overkill in this case.
Those are all the ways I can think of, but someone else might have more
ideas.
--David
--
David M. Marcovitz
Director of Graduate Programs in Educational Technology
Loyola College in Maryland
Author of _Powerful PowerPoint for Educators_
http://www.loyola.edu/education/PowerfulPowerPoint/