It is so easy to get interested in something (including Stackoverflow) and lose a total track of time doing it, even when you have a lot of things to do.
What tools and techniques do you use to track your time.
I have come across hamster-applet, promodoro technique. RescueTime seems a nice tool to introspect, but there is no proper front end for Linux.
Lifehacker gtd has some excellent tips, including tools. Which of these tools and techniques work the best in a programming scenario.