I've never done it, and thought it wasn't possible. However, http://www.indezine.com/products/powerpoint/ppflash.html provides links to "tools and tutorials that help insert Flash content into PowerPoint" and "shows you how you would manually insert Flash content in PowerPoint." That seems promising, but I can't tell you how hard or easy it is.
The alternative to me seems to copy the Flash file from your temporary Internet-files to some folder, then write a simple and short html-page calling it (just copy that piece of the original page). Then you don't need a Internet connection to view it in Internet Explorer.
Hope this helps.
Kees
I am using PowerPoint and I want to add some animation to my slide show. My project is about the City of New Orleans. It is for my Govt. class. I have to do a time line about the hurricane. I found some time-lapse animations on-line at some news WebPages about the hurricane. I was wondering is there anyway you can copy them on to your computer so I can add them to my slide show? They are player threw Macromedia Flash Player. I will not have the net at my college while get my slide show. So, I cannot link and go to them while I am giving my slide show. Can someone help?

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