Many times when we prepare slides using power point, we'd be in need to place an image with transparency supported , mostly to make it go well with the background color. If the background color is white, we wouldn't be a problem even if the image did not support transparency. But if the background color of the slide (PowerPoint) is not white, we cannot fit in the image that comes with a white big. Often when we pick a graphic from the web, it comes like that. To correct this image's background, I would usually open Adobe photoshop CS2 and manually remove the white colors inside the image and make it transparent and save it as PNG file. I've it pretty time consuming. Anyway the cool feature that comes with Office 2010, is "set transparent" for any color.
Happy powa pointing!