When we travel abroad we make a point of collecting all the coins in the local currency. It can be fun chasing down good copies of the less common coins, and makes a nice momento of the trip. Along with a set of calipers and a 5x10 license display frame, the Glowforge makes it pretty easy to sketch up a small coin holder to keep them arranged and in place.
The board is 1.5mm MDF, painted dark green. Coins are pressed in place. These two frames have currency from Canada and Bermuda.
The toonie is great. We had to look high and low to find the special glow in the dark one. Most of the people thought we were crazy when asking about them.