If you are using Openoffice for a presentation and for some reasons the program is not responding as fast as you were expecting (or as slow as if you want to throw your chair and everything out of the window) I suggest you to try a small plug-in in order to be able to reduce the size of the file you are working on.

It is called Sun presentation minimizer, and eliminates all sort of unecessary things that make the file too slow for your not-extr-powerful-not-so-multitasking PC, such as delete the non-visible portion of the images that have been cropped, or by transforming OLE objects into non-interactive lightweight images. I must say I found it helpful. And it seems to work for Powerpoint too.