Toyota has released some advice re what to do in their vehicles if the accelerator pedal becomes stuck:
• If you need to stop immediately, the vehicle can be controlled by stepping on the brake pedal with both feet using firm and steady pressure. Do not pump the brake pedal as it will deplete the vacuum utilized for the power brake assist.
• Shift the transmission gear selector to the Neutral (N) position and use the brakes to make a controlled stop at the side of the road and turn off the engine.
• If unable to put the vehicle in Neutral, turn the engine OFF. This will not cause loss of steering or braking control, but the power assist to these systems will be lost.
• If the vehicle is equipped with an Engine Start/Stop button, firmly and steadily push the button for at least three seconds to turn off the engine. Do NOT tap the Engine Start/Stop button.
• If the vehicle is equipped with a conventional key-ignition, turn the ignition key to the ACC position to turn off the engine. Do NOT remove the key from the ignition as this will lock the steering wheel.
Another excellent source of advice is an article at Car and Driver about coping with unintended acceleration.
Via Reddit, where there is an informed discussion thread.