This one is super easy to enter for U.S. and Canada residents! Peterson Guides is giving away 25 copies of their moth poster in celebration of Moth Week 2015. Just fill out the form and you're entered! Winners will be notified on July 28th so enter before then to get your name in the running.
The poster is a promo giveaway for the popular Peterson Field Guide to Moths of Northeastern North America. Good luck!