You said
"http://www.mysite.com/blue-widgets.html/" to resolve to
"http://www.mysite.com/blue-widgets.html"
which is the exact same url?
If you want to redirect users who visit
http://yourdomain.com to
www.yourdomain.com you could use something like the following in your .htaccess file but you need mod_rewrite available on your host.
RewriteEngine On
RewriteCond %{HTTP_HOST} !^www\.example\.com$ [NC]
RewriteRule ^(.*)$ http://www.example.com/$1 [L,R=301]
A quick search in a search engine for htaccess redirection will return a lot of results with examples.