A while back, I made an offhand comment about something being one of the seven deadly sins of programmers (/programming/developers/software engineering/coding/...).
At the time, I really didn't have 7 things in mind, but after a little thought, I came up with what I think is a good list.
But before I write the first entry, I'd like you to spend 5 minutes and write down your list of deadly programmer sins. Though 7 is the canonical number of sins, your list can have any number of items. After I've gone through my list, I'll do another post where you can share your list.
[Update: Sorry I wasn't clearer. Write your list down, and then post it when I'm finished. Or post it now on your own blog if you'd like]