I noticed that somehow Sparkfun inventor's kit gives two types of transistors. I noticed this when i was doing a project with DC motors and Arduino. It wants us to use
P2N222A18in my kit) and one of them was marked saying that, the other says nonsense! The one marked is the one you should use, not the one with the nonsense, or then perhaps you might spend 1-3 hours just why it isn't working! When it works, it is hard to see but gives a buzzing sound. IF it still dosen't work, go here:http://blog.ringerc.id.au/2012/01/sparkfun-inventors-kit-circ-03-motor.html
Hope u have fun!