Want to quick tutorial on removing background from images, this post shows you how to use the new Remove Background tool of PowPoing 2010 on pictures.
"The Remove Background button will isolate the foreground object in an image and remove the background elements."
Here's the original image of a skateboard:
Here is the final image:
If you click the "Remove Background" button on the Picture Tools Format tab, you'll enter the Background Removal contextual tab.
You'll also see that PowerPoint makes an initial guess about what to remove. In many cases this will be the end of the story, so you can just click "Keep Changes" and move on. This all depends on the characteristics of the picture and which object you are trying to isolate. When the guess is incorrect, there are a couple of quick steps you can take to get the result you want.
First, drag the rectangle to fit around the object you want. Then, click the "Mark Areas to Remove" button and draw lines over the unwanted areas, such as the wood floor. If part of the object you want is under the purple mask, then use the "Mark Areas to Keep" to make sure they aren't removed accidentally.
In a couple minutes you'll have just the areas you want, and everything else in the image will become transparent.
As a final step, you may wish to use the crop tool to remove transparent areas so that the bounding box fits tightly around the object.
Since it's just a picture, you can apply effects, rotation, and scale just as you would to any other picture in PowerPoint (notice in the "final picture" above how the shadows project only from the isolated skateboards).