Do you have Firebug for Firefox (press F12 to bring it up) or the Developer Tools (Ctrl-J) for Chrome? They make it trivial to toggle/edit CSS attributes on webpages.

In GWAN's case (using Firefox) the rule was:

p, h1, h2, h3, h4, ul, ol, legend, label { -moz-user-select: -moz-none; }

There are already quite a few out there. Search your favorite browser's extension archive for something along the lines of "enable right click." (For example, Firefox has RightToClick.)