Toyota Repair: Flashing OD Light, vehicle speed sensor, d light

Question
Driving at 70 mph, and first noticed speedometer jumping up and down...car also lerch a couple times.  Exited, and notice shifting was unusual (higher RPMs than normal).  Stopped car, checked tranny fluid, seemed o.k.  Got back in car and started moving, O/D light is flashing, speed is not registering on speedometer and shifting is erratic.

Ideas?

Answer
I'm not sure what to recommend without knowing the year/model but in most cases the O/D  light will flash because the computer has logged a trouble code, the first step is to find out what the trouble code is so some kind of diagnostic procedure can be started, since the speedometer stopped working there is a good chance that the problem is the vehicle speed sensor or the speedometer itself.