About ten hours a day six days a week (about two hours of those a day are just for fun though fun and work blend for me as I find most of my work fun), about the same time that anyone at the top of their profession spends on their work.
So while I’m off the computer and in bed last night, somebody comes into my chat room and leaves this:
"OhtheIrony: Luke, Luke, I am a fan of your site but I find the amount of time you spend on the computer to be disturbing. How many hours a day do you spend on here?"
Oh, the irony.