The Arduino itself isn't really capable of playing music on its own, but add an Anniken Andee shield, and you're good to go!
The String2String project is a blackboard that has been converted to smart-board, using a clever technique of reading the chalk position.
Average Clock takes a bunch of real-time clocks, and calculates the average. The result is a more accurate clock than a single RTC.
The 3D pad is a touch-less gesture control sensor shield, adding 3 dimensions of control, allowing futuristic style 3D gestures.
This GoPro time-lapse pan controller helps add an extra dynamic to time-lapse photos, by slowly panning during the shots.
Kerimil shows us how to communicate between Arduino and a custom Android app. It uses Bluetooth, and the MIT App Inventor for the app code.
The TouchUp is a custom project to control a hospital bed from an iPad, and was designed for a patient with MS.
This novel project helps maintain your plants. When the soil gets too dry, the little emoticon changes to show a sad face.
Poké-O-Matic is a great little project that automatically seeks out and captures shiny Pokémon, by combining a Nintendo 3DS and a Teensy.
The Xmas Pi lets you remotely control the lights on a Christmas tree via your web browser.
The mirrored shack is an unusual, if elegant Art project. It is powered by solar powered LEDs, and seemingly blends into the background.
The Multi-Touch is a touch controller featuring an 8x8 grid of LED loveliness.