I’ve really been enjoying Zachary Abel’s series of posts on Wythoff’s game [Wythoff’s Game: Red or Blue?; A Golden Observation; The “Fibonacci”est String; Wythoff’s Formula], over on his blog Three-Cornered Things. The Fibonacci numbers show up in the strangest places!
More generally, if you haven’t seen Zachary’s blog before, go check it out. If you enjoy my blog, I think you’ll enjoy his too.