Thanks to those who suggested Resharper. This gives me another reason to love it even more. Just to be specific about where this lives – JetBrains call it CamelHumps (cute) and you can switch it on using the menu:
Resharper -> Options -> Environment -> Editor -> Editor Behavior -> Use CamelHumps
… in older versions of Resharper, it is;
Resharper -> Options -> Editor -> Use CamelHumps