I really like the Stack Overflow website. You can watch the homepage content change constantly as programmers post new questions. Sometimes a really interesting question pops up like this one:

"What real life bad habits has programming given you?" http://stackoverflow.com/questions/164432/what-real-life-bad-habits-has-programming-given-you

Read some of the answers to get some great insight into the mind of a programmer, a useful field guide for anyone who has to live with one ;-)

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Updated 2021 : note that the above post is from 2009, but is left here for archival purposes. Sadly that question has been removed by Stack Overflow moderators! Since I wrote this, my opinion on Stack Overflow has waned as inexperienced programmers have come to rely upon it too heavily, especially when it comes to blindly copy-and-pasting code from there. I have unlinked the dead external link.