Clipping Masks

I've just begun experimenting with clipping masks.  What's that, you ask?  Here's an example of a clipping mask I found online:

You stick in in Photoshop and "clip" a photo or paper to it.  The results look like this:

You can use this technique with any shape your heart desires!
Here's a random clipart image I had on my computer:

Here it is after clipping some digital papers to it:

What do you think?