Are you aware that many Web sites (one third of the top 100 U.S. sites) are sending your passwords in the clear? If you are on an unsecured WiFi network (e.g., in a coffee shop), your passwords could be eavesdropped by someone around you.
Sounds scary? You should check out Piigeon.
Piigeon monitors whether Web sites protect your username and password when you sign in. For most sites, the cursor will change, telling you whether your password is encrypted or if it could instead be intercepted. Over time a report of your password safety is created. Piigeon also suggests whether you should change your passwords based on how your passwords are shared across sites.
For more details, please see http://piigeon.org.