If for various reasons you are forced to allow someone else to present the OpenOffice.org Impress-made stuff that you produced, chances are you would worry that the presentation would be changed unnecessarily. You need protection for some data in the presentation, like financial data.
One solution is to export the presentation to PDF format. Of course, animation and effects will not be saved to PDF. At least, the static look (object positions, color, font, etc.) of the slides will be retained. Also, any PDF reader has the feature to display each of the slides in full screen, so it feels like you’re also viewing the slides on Impress.
(Note: I wrote this entry as my reaction to Mr. Jerry Liao’s article on inquirer.net. He advised on his article that PowerPoint presentations may be protected by saving each of the slides to .jpg and then insert each of the images to another presentation file. Isn’t that tedious?)