While working on some application security requirements for a client, I came across this little nugget about cracking pgp passwords using a cloud.
It's interesting to see how easy it has becomes to brute force passwords using distributed computing. While brute force attacking passwords for the average person is still time-prohibitive, even with a cloud, the ability to reduce password cracking times from years to weeks is impressive. Cracking performance will continue to increase as distributed computing becomes cheaper, faster and more widely adopted.
Take a look at the article and think of how this could affect your data: Cracking Passwords in the Cloud
If you haven't started to really focus on application data security, perhaps you should...