The Buck Book: All Sorts of Things to Do With a Dollar Bill — Besides Spend It, by Anne Akers Johnson
I have a weakness for Klutz books — they seem to be universally easy to follow, fun, and fairly usable for clowning. This is a good example. In essence, The Buck Book is really just a glorified origami book; but a very good origami book, focusing on what can be folded from a dollar bill. As you can see in the illustration, it includes a ring, a ring with a dime as the ‘gem’, an elephant, a peacock, a jumping frog, and more.
Like all of the Klutz Press books, it’s well-written, clearly illustrated, with step-by-step instructions for making all of the creations. It even includes a dollar bill to start you with.
Where could this be used? Think of the giveaways for a birthday party — a dollar bill ring would go over quite well (depending on the age of the child). You could give them away as walkarounds, although that would get very expensive very quickly 🙂 Of course, you could go to your local dollar store, & get a pack of ‘fake’ dollar bills instead  — others get special dollar bills printed with their faces, as well as their phone number and website URLs.
If Origami is something that your clown does, would like to do, or is interested in looking into it, I recommend this book. Even if you’re not a clown, it makes a nice way to entertain children, grandchildren, leave tips in a restaurant, etc.
I rate it 4 clowns  
 on a 5-clown scale.