[cooperadymas]

Would like to say this was my own idea, but I stole it from another HNer in one of the thousands of "what should I build?" threads. Do a search for Excel or Google Doc templates and find one that is popular. Build it into a single-purpose app like this. Great for building a little portfolio, making yourself known, and generally making the web a better place.

And, like you said, it's shockingly easy :)