Q: would you not want to compress all the pictures before distributing the presentation?

It sounds to me like you want the end users to be able to compress the picture, similar to a navigation Action Button, and I can't see how they would need to do that?

If you just want to make the file size small, PP2003+ has a Compress Picture option. From Help:

  1. Select one or more pictures (picture: A file (such as a metafile) that you can ungroup and manipulate as two or more objects or a file that stays as a single object (such as bitmaps).) in a file.
  2. On the Picture toolbar (toolbar: A bar with buttons and options that you use to carry out commands. To display a toolbar, click Customize on the Tools menu, and then click the Toolbars tab.), click Compress Picture http://office.microsoft.com/global/i...ZA060437461033. Note If you do not see the Picture toolbar, point to View, then point to Toolbars, and then click Picture.
  3. Select the options you want.
Note Selecting the Delete cropped areas of pictures check box discards the parts of the picture that were hidden during cropping (crop: To trim vertical or horizontal edges of an object. Pictures are often cropped to focus attention on a particular area.).

Paul