If you'd like to run a slideshow continuously without being there- for example, at a trade show kiosk? Do this:

• With the presentation you'd like to run open, select Slide Show | Set Up Show.
• Under Show type, select "Browsed at a kiosk (full screen)" then click OK.
• Select Slide Show | Slide Transition to display the Slide Transition task pane.
• Under Advance slide, select "Automatically after" and set the time after which you want to advance to the next slide.
• Click Apply to All Slides.
• To see the show in action, click Slide Show or press F5. To exit the show, press Esc.