I just ordered a Chr. Ward c900 monopusher. I can't stop ranting and raving about this watch. It uses a Unitas 6497 mated to a column wheel chronograph module that's operated by a single pusher that also happens to be the crown. I know there are other great watches based on a crown operating system such as the Habring COS(7750). The only watch that I have seen that has an even slightly similar mechanical setup is Lange Heyne Albert monopusher. I believe they are both J. Jahnke creations.