For The Verge, Alexis Ohanian (co-founder of Reddit) visits New York City start-ups. He met in the second episode with RapGenius‘s founders. A 20-minute video well worth watching.
Not a big fan of the founders’ style and attitude though, but I love how simple their idea is and how well it is executed. I use the website daily, not to annotate, but to understand rap lyrics. A true goldmine.