My dog loves to chase a laser pointer and needs regular exercise.
-3d printed bracket and laser housing
-Micro servo from here: http://www.amazon.com/gp/product/B006RCLJPA/ref=wms_ohs_product_img?ie=UTF8&psc=1
-Home brew laser driver: 2N222 with laser connected in collector (+to 5v) and base connected through a 1k resistor to Arduino pin. Emitter to ground.