Awesome Pokemon Hack — each inventory item has a number associated with it, they are kept at a particular memory location, and there’s a glitch in the game that executes code at that location so … you can program by assembling items and then triggering the glitch. SO COOL.
The Mature Optimization Handbook — free, well thought out, and well written. My favourite line: In exchange for that saved space, you have created a hidden dependency on clairvoyance.