The Trapcode AirPaint. This application, designed for iPhones allows you to paint in the air using the built-in accelerometer to estimate how you move the iPhone when painting a storie in the air.  Drawing it's inspiration from Pablo Picasso and Gjon Mili, who used a camera with a long exposure time to create such light art in 1947, this would be an awesome and unusual gift to give that pal of yours that swears they don't miss BBM.  Plus, it's only $.99!

[Thanks Nick!]