Over on Hardware 2.0 I've got a post showing you how quickly weak Windows logon passwords can be cracked using a tool such as Ophcrack.
The results were quite staggering. In less than 50 seconds three weak passwords had been recovered (shame on you pcdoc, Fred and Betty … I’m not letting you on my systems again). However, two much longer and more complex passwords (one consisting of alphanumeric characters, the other more complex) survived.
If that doesn't get you motivated to change those weak passwords this weekend, I'm not sure what will!