Mike Henke reminded me of this slick little tool called varscoper. Pass in a directory and it will ferret out all the places where variables are not correctly scoped. For example, it will sshow where you have not correctly var'ed variables in a function. The project was produced by Mike Schierberl who's blog has some excellent goodies and tips.
varscoper won't catch the cfhttp scope, but it would catch a variable declared as a result attribute. Either way, it could save you some headaches - especially when dealing with a large pool of code, or taking over someone else's code.