cheap security

i dont know if anyone else had this idea, but i have always been concerned that some one may try to steal my car. well i dont have the most money, and am saving up for an alarm, but for now i recently placed a switch inline with the wire going from my starter relay to my starter. so in order for the starter to turn over, the switch needs to be switched. i know its simple, but someone stealin a car wouldn't think to spend time lookin around, i would assume the battery was dying, so yeah. i thought it was a good idea and felt like sharing.