I've been authoring a post on solving interview questions in map/reduce between experimental runs myself, so I guess I already hit the "bored graduate student" point too...
I remember having to resist the urge to map/reduce everything in interview questions :P. Somehow, I don't think interviewers want to hear how you'd use a cannon to solve a tiny problem.
Why use MapReduce when you can use the real `map` and `fold`?
because they're stupid?
hurray for java. the most verbose and dog slow language ever invented.