Hey Slim-Slag
I don't think anyone has a problem with being corrected, but it could be done in a respectful manner!!
As for the Visas, I suggest that you either call the US Embassy in london or take a look at the web page! I have a friend that was turned around for exactly what you said you could do!!!
Take a look at:
http://www.us-immigration.org/visa_vistourist.htm
It plainly states is you are to study that you need another Visa - prove me wrong and I will be happy to rescind my stance!