It would seem I am wrong about the ECM in our cars. I found this while researching a RAV4 specs topics. Apparently, it is possible to reflash the ECM in a 2AZ application. That certainly helps understand how Scionspeed was able to say he thinks there is a way around the speed limiter (we all want this if we do get turbo systems installed, it would suck to have 300 hp and a 127 mph top speed limit).
Anyway, just wanted to set the record straight. I found the tools. It's not cheap. About $6k for everything before convincing Toyco to put me on distribution for TSB and software updates to recalibrate the ECM. My bet is they've locked down most of the stuff you'd want to toy with anyway. That's a big hurdle for someone who doesn't have a shop.