The book we're giving away today is Where the Sidewalk Ends by Shel Silverstein. Here's how you can win a copy:

Come up with a great slogan for a mental_floss jumper. We'll choose our favorite early next week. If we like it so much that we want to produce it, we'll also send you a check for $125!

For inspiration, here are a few items from the kids section of the mental_floss store:

[If you see something you like, get it for 15% less! Just enter the coupon code SCHOOLDAYS before checkout. Offer ends Monday, August 16th.]