I did the slides using openoffice in linux. I was quite satified with a diagram with (transparent) rectangles overlaid and stacking on top on each other. While you look at the animation, you can really see than the as more ractangles are stacked up, the colour changes (like the alpha-blending effect). Then I save as powerpoint file and bring to office to edit, that effect doesn't show up. Simple because in powerpoint, transparent effect is actually just a dotted pattern in the colour. That means, no matter how many layers you overlay, the colour still remain the same. And the colouring effect is important to my presentation. And now I have to adjust the colour of *each* layer so that the colour changes as you stack in my layer. It's new to me that something can be done in OpenOffice, but NOT powerpoint.

HonL