How can I insert a document property (e.g. the author's name) in a slide in PowerPoint 2007? I know this can be done in Microsoft Word, but I can't find how to do it in PowerPoint.
(The idea is that with a document property it is easy to change e.g. the content of the footer in all the slides, even if you use different master pages. If there is a different solution, that would be fine as well.)