At the end of many types of presentations, presenter's acknowledge contributions, provide follow-up resources, list contact information, give credit to important sourcing, acknowledge the efforts of those who provided invaluable services, etc. One of the many ways to do this on one slide and one click is to display all this important information like movie credits.
The credits can be one text field or several text fields and include graphics. Just lay everything out and group it – don't worry if it hangs over the bottom of the slide or where it begins on your slide. Then format the group to animate as "Credits" in the Entrance animation menu. When in slideshow mode, the group will automatically move below the screen and slide upward until it reaches the end. You can make it as long as you wish and set the speed you wish. This is a really nice way to provide lots of information and have it run passively in the background as you end your presentation and thank your audience.
This method only works for onscreen/projected presentations.
Note: the flash may be a tiny bit "jumpy" due to the buffering, but the credits flow smoothly when projected from a computer.