You can do your bit for the Internet by showing a warning to IE 6 users in your Rails applications, or disabling it completely for those users, encouraging them to upgrade their browsers (or nag the relevant Sys Admin).
Firstly you need to install the UserAgent plugin by Josh Peek:
script/plugin install git://github.com/josh/useragent.git
You then need to copy this script to your lib directory.
If you want to just show a warning to people using unsupported browsers, you’ve got a valid_browser? helper method:
<%- unless valid_browser? -%> ... <%- end -%>
Or you can disable access completely:
render :action => '/path_to_template'