Depends on mileage...if its high, it could be the fuel pump, fuel pump relay, or the equivalent of the ignition module. You could try to buy some quickstart and squirt it into the air intake. Wait a few seconds and crank it. If it starts and then cuts out, then the spark is fine but there is no fuel. If that is the case, then its either the fuel pump, its wiring, fuse, or fuel pump relay (the device that cuts the fuel after a crash). Its annoyingly probably an intermittent fault, but the quickstart test might give you a clue.
Mike, May 2010