Tool for easy PC to Arduino communication for prototyping?

dmayman:
I'm curious if there's some software out there that provides an easily configurable GUI for modifying values in an Arduino sketch. For example, something that runs on a Mac or PC with some on-screen buttons and sliders that I can map to variables within my Arduino code. I'm imagining something meant not for the end result, but just a tool to help find the right values (like dialing in colored light just right).

I know this can be written from scratch in Processing or something similar, but I'm wondering if something already exists with this intent.

Thanks!

I just started with it but perhaps this could be a solution for you