As you know, I advocate keeping everything up to date on your PC, not just the OS. Applications, accessories and browser plugins are all subject to security vulnerabilities. Mozilla’s Plugin Check makes it easy to see if your browser plugins are up to date.
The beauty of this site is that it works with all popular browsers as noted by Steve Gibson of Security Now!:
The big news is they’ve decided to expand this service beyond Firefox, which is so cool. They’re now offering it for not only Firefox, but Safari, Chrome, Opera, and IE.
Just do it!