I wrote a script with MEL in my spare time that allows you to easily create controls for rigs. If something is selected, controls will snap to the object upon creation--otherwise it will simply create the control at the origin. It also features a size slider and an 'align objects tool', useful for snapping existing elements together. The script is super simple, but it was a great learning experience for me. There's a download link below for anyone interested.
You can download the script here.
