For the past 22 years my church has shown the Living Christmas Tree program to tell people the real meaning of Christmas. This year, Chris Nesbit and I built a Arduino Yun powered automated Christmas light system to power the lights on the Living Christmas Tree.
Have you ever wanted to wirelessly control power outlets from your phone? You could buy a Belkin WeMo Switch for over $40 for 1 outlet or build your own with 5 outlets for under $35 if you already own a Raspberry Pi. Hopefully this post will guide you in the right direction.