Note: You will need those red and blue 3D glasses, so dig through your cereal boxes. If you have a younger sibling (I have a younger sister) you might want to check if you have the Spy Kids 3 movie, it comes with 3D glasses. Those were the only ones I could find in my house.
Or you can make cross eyed pictures, just click the link to see what I mean. I can cross my eyes so I can see them in 3D that way, but is is harder than just using the glasses to see them, and some people can't cross their eyes.