We're on a thing about Houdini and coins, and it took us back to the days when, with the aid of Coco the talking parrot, we used to teach Magic to the would-be-initiates of old San Francisco.
We promised never to teach anything cheap or cheesy, so the very first Trick in the curriculum was Houdini's Four-Coin Assembly, an excellent variation of which you can see in the video.
It's a beautiful illusion and not too difficult to learn. We billed it as "Houdini's Favorite Close-Up Trick," based on his own writeup which appears in Houdini on Magic. It kept them coming back for more.
(We note that Mark Wilson borrowed Houdini's exact version for his own course on magic.)
