As recently as today I thought IPython might be worth looking into -- I've heard too many good things about IPython to ignore it, but I didn't really know how to get started.

I guess I don't have that excuse any longer! My only concern is that my mind will have trouble adjusting to the evolving state of the "app" I'm working on -- it seems like values in lines above others change, which then change values at other places, not just below the code? Will take some getting used to.