[imhoguy]

You need to shorten the feedback loop to become productive. Maybe you could optimize your environment to operate on smaller data sets during the development? Introduce sampling, local caching etc. Then once you feel confident about the code you run it over the final data-set.

I often find myself stuck staring at screen when some lengthy process occurs. What helps is adding progress indicator, ETA clock, some audible OS notification on finish. Or better take a walk and get a SMS once the process finishes :)