Submission + - 12th Internet Problem Solving Contest
IPSC is what you could call "a programming contest with a twist". Over the years, the problems always push the boundary and go beyond the usual stuff you see in a programming contest.
For example, in past few years the contestants had to understand how arithmetics in computers differs from the one in mathematics, produce a sequence of cache requests that generates many page faults, solve a logic puzzle given as a flash game, or recognize images to evaluate a rock-paper-scissors game.