Couple times a day (2-3) except during hunting season when I don't spend much time on the computer other than to check email.
I was recently promoted to Deputy Chief and on Monday I began the first 8-5 gig I've ever worked in my life, and the first time I've ever had a private office. Probably 60%-70% of my workday is now working on the computer.
Like Gaffey, this week I've left this site running in the background and have been dropping in for a few moments when I need some down time. Nice break when schedules, equipment, budget concerns, and the myriad other admin duties I now have start to get tedious...