Create MOVIE CREDITS-style crawling text
If you'd like to create a presentation that includes movie-style "crawling" credits text, here's how you go about it:
First, type your text, all of it, in a single text block and format it to suit. Don't worry if the text runs off the bottom of the slide. In fact, if it doesn't, you probably don't have enough text to make a crawl effect that works.
Right-click the text and choose Custom Animation from the pop-up menu.
In the Custom Animation dialog box, click the Effects tab.
Put a checkmark next to the text object that represents your text box (it'll show up as selected in the preview window when you do this).
Choose Crawl, From Bottom as the Entry Animation effect. If you want the entire text box to go by at one time, choose Introduce text: All At Once and remove the checkmark next to Grouped By. Click Preview at any time to get an idea of how the effect will look on screen during playback. Click OK once you have the effect you want.
Finally, move the whole text block completely off the top of the slide. Now when you play your presentation, the text will crawl or scroll from the bottom of the screen and disappear off the top. If you'd prefer to have it disappear somewhere below the top, draw a rectangle that extends from the top of the slide down to where you want the text to disappear. Give the rectangle no outline and a fill that matches the background.
Don your black cape and Darth Vader helmet and let the show begin!
And here's a neat trick: to learn how to make the text fade in as it appears and fade out as it scrolls off the top, see this tutorial at PowerPointBackgrounds.com
And if you use PowerPoint 2002 or later, PowerPoint MVP Echo Swinford has a sample slide with "Star Wars-type" crawling credits that uses an upward motion path, grow/shrink emphasis and fade exit. Each "paragraph" of text is in an individual textbox.
Bill Dilworth's How to animate/display long credits lists has even more useful tips.