You could try jumping the solenoid on the starter to see if it will start to turn over.
If you do this be very careful. Make sure it is in park and if possible have someone inside the car to hold the brakes just in case something crazy happens.
EDIT Another thing just occurred to me. Make sure the car is fully in park. You could also try moving the shifter to neutral andtry to start it. It could be a neutral safety switch issue.