If you have MS Excel installed, and you do any sort of form based programming, this trick is right up your alley. Excel’s drag to auto-number is one of my all time favorite features. Often times I end up working on large form based applications and love firing up TextPad and Excel to help shortcut the time it takes to write my form handling code.
This video shows this trick in action. Unfortunately the code is barely legible due to the zoom level, but the concept should still come through.