I’m about to launch a new site and was looking into a quick and easy way to advise users with older browsers to upgrade. A bit of a Google revealed Browser-Update.org. They have a simple script that you add to your site and it will not only inform them that their browser is outdated, but also provide them with instructions on how to replace it.
All you’ve got to do is place their script on your site somewhere:
You can customise the versions by visiting their site and using the script generator. Once you’ve got it setup, users with older browsers will see a bar at the top of their page:
Let me know if you come across any other useful plugins.