Twilio has partnered with Zappos for an API Hack-a-Long Contest where participants will be judged by Zappos employees and the winner will receive a Kindle Fire, chosen by Twilio using its own API. The contest features three categories: Best Overall Application, Most Fun and Weird Application, and Best Mash-up Application. Participants have until Friday at 5pm PST to submit their entries, with more information available on the Zappos Developer Blog.