It's true about currencies...the bezel is a pretty sweet money converter.
What's a whiz wheel? I've never actually flown with one...fuel management involves setting up a complex algorithm, usually written down on scratch paper and promptly thrown away, to calculate burn based on winds, proposed route, weight, fuel density, speeds, etc all of which is laid out in a log. Once aloft, you set a nice easy number that can be divided into minutes real easy (say, 600#/Hr) and turn your fuel log over so you can scribble shit on it once ATC completely reroutes your flight around a line of t-storms and effs your numbers to hell anyways. After that it's all in your head anyways.