I use Apache's mod_rewrite extensively on my site to generate clean URLs. It is basically matches a regex to a url (similar to Django's URLConf). I noticed that, while links like /news/ worked fine, /news (without the backslash) would generate a 404. To fix this, at the bottom of my .htaccess file, I added the following:

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)[^\/]$ $1/

This snippet tests for a 404 condition (no matching file or directory) and if it is true, it tries the RewriteRule, which basically will take any URL that does not end in a backslash and try appending one. Works great!