Via an article in the Daily Mail, we learn of the creative instincts of one Grant Thompson. His YouTube channel has many videos of his various and sundry projects, but the one that caught the newspaper's imagination (and mine) is the way he used a four-foot Fresnel lens from an old rear-projection TV set. As background information, he describes acquiring and extracting it in this video clip, and making a frame for it in this one. Here's how he put it to use after those preliminary efforts.
I was going to say "Cool!", but that'd hardly be appropriate in this case, would it? Now, where can I find one of those old rear-projection TV's?