i doubt your gonna check back after all this time, but its only know ive been shown the one handed drum roll.
Again, it was at the John Blackwell clinic. He showed us exactly how to do it, but it is a lot harder than you think. Apparently there are a few ways of doing it, and Buddy Rich had a way. John did it by putting the stick flat on the drum, but more to the left side of the drum so that the middle of the stick is sitting on the rim, but the tip is laying on the head, about an inch from the rim.. He then pivoted the stick on the rim by just holding the stick loosley, and moving his had up and down. He had to move his hand extremly fast to get something close to a consistant roll.
from just watching him, i would say not to bother. He didnt play anything while doing this roll, because he was so busy concentrating of keeping his body still, and his hand and lower arm moving so fast. Even when he got it going, it didnt half as smooth as a normal single stroke open roll.
EDIT: and this:
www.onehandedroll.com