This same thing happened to me two days ago...it was so weird driving with it like this. Mine has stuck before, but usually only when I stop...this time it was, as you had mentioned before, like I was in cruise control. At one point when I stopped and had it in neutral, it revved itself to 4000 rpms!!

If you figure out what the hell the problem is...I'd be grateful to hear the solution...and my throttle and cruise cbles dont seem to be sticking at all...so weird.