What I was counting in the graph was transactions in the blockchain - surely speculation remains completely within an exchange and does not enter the blockchain at all? Daily transactions peaked at about 30,000 transactions/day in June, about the same time the price peaked on the exchanges. Right now there are about 13,000 transactions per day. What were the users doing with their bitcoins in June that they are not doing now?
The flip side is that if the growth rate in the mid section of this graph were to continue (63% increase per month) then bitcoin would match visa for transaction numbers (4000/sec) within 2 more years. I suspect it's going to take a little longer than that, so there should be some growth bumps along the way.
Simon
I was not clear if gox could really be trusted so as soon as I purchased my coins,so I sent em to myself.