Elvis Alive- the best place to start if you are having technical difficulties is the Elvis Hack Bot Instructables. Here you can review the complete hack, post questions, read tips and find solutions found by other Elvis Hack Bot users.
Slot Machine. This tutorial is in process, and it quite involved as the slot machine uses Raspberry Pi to run the game (using pygame) and an Arduino to control the real-time features (coin acceptor and coin dispensor). Also it turns out the designing an engaging probability system is pretty interesting.