Websites
Think Java's all that and a bag of chips? Great; use this site from Princeton to test your recursion chops using everyone's favorite coffee-based language.
All the recursion you know and love—minus a specific language. Aw, yes.
Love fractals so much you want to make your own on your Windows computer? Check out this generator to fill that fractal-sized hole in your heart with smaller, repeating holes of the same shape.
Tips and tricks on how—and when—iteration should replace recursion. No matter how much mathematicians love it.
Even toddlers can practice recursion if they play the Towers of Hanoi game. Get your recursive steps on here in this virtual game.
Check out the recursive art UPenn students made. From code.
Human subcultures defined in a way that only xkcd could do it.
Everything you wanted to know about recursion in the exciting, informative style you've come to know and love.
Articles
Recursion isn't just for mathematicians; it shows up all over the place in nature, too. Check out what WIRED rates the most stunning examples of fractals you'll find IRL.
Video
Fibonacci, the way it was meant to be: doodled.
African culture and architecture is full of fractals (and therefore recursion).