A few months ago at CFUnited, Intergral released FusionDebug, a plug-in for the Eclipse platform that provides interactive debugging services for ColdFusion applications. I've never used a debugger before (I was in the group that Charlie Arehart refers to in his Why Use FusionDebug When You Can Just Use CFDUMP? blog post.
All I can say after playing with it for a little while is WOW! I had been working on a project that uses Flash Forms and remoting to call CFCs and had been struggling with finding out what exactly was going on inside some of the methods at specific times. I absolutely love this debugger for exactly that reason.
I know I'm a little late to the party, but as I said in my inaugural blog post, this career move into CF consulting has giving me a bunch of opportunities to try new things.