But please, donate a couple of bucks to their charity drive.

Did you know that there's a National Flip Flop Day? I didn't. Frankly, flip-flops are bad for my feet (and everybody's feet, really), so I tend to avoid them. But if it means that I'll get a free smoothie out of it, then sign me up!

Today at Tropical Smoothie locations from 2 PM - 7 PM you can get a free 16-ounce orange, banana, pineapple and mango smoothie if you're wearing flip flops. Donations aren't required but are being accepted for Camp Sunshine, a nonprofit that provides a Maine Retreat for children suffering from life-threatening illnesses.

So, in short, go get a free smoothie, and drop a dollar in the hat for the kids.