it seems like there must exist some sort of 'benign spyware' you can install on your computer, which monitors what programs you have running (and when each one is the active window). it could automatically generate reports of your top 10 most frequently-used programs, most used in the recent day, week, month, etc. this is sort of like the "top visited websites" feature in Google Chrome and other browsers, except extended to all programs on your desktop. think of it as a layer on top of 'ps' or 'top'.
