A number of my projects use Arduino technology to create 'smarter' products. The Sleeper Steel Chair featured under 'My Designs' incorporated sensors that could detect when a user was sitting and how long they remained sedentary before projecting a live animation through Processing.
The project below used Arduino to create an intelligent clock game that would first, set a target time, before checking the user's answer and advising whether to move on to another time or have another try.