In case you didn't know this, simply sending things to your recycle bin does not actually delete it from your computer, even after you empty it. You may not care a whole lot about this, but if you ever sell your computer or recycle it, you should care. It is quite simple for the most novice identity thief or Nosy Nick to track down your "deleted" sensitive files.

PC World has put together a short and really helpful video on how to properly erase your hard drive when you are through with it (sledgehammer instructions included)

How to Completely Erase a Hard Drive