I try not to go to my desk unless I have the program fully formed on paper already. If I go to the desk with a half-baked idea I will either just stare, or I will read pointless sites like this one all day.

I used to have a computer that for security reasons was only connected to revision control, build-and-test systems, and production datacenters. No outside access. Those were the days, frankly. I don't know why the company got rid of the policy that required them, but it really improved not only security but also productivity.