Even more useful is ToFu ( http://www.macupdate.com/info.php/id/12575/tofu ). It's a free standing app but it also provides a Services Menu "View in ToFu" item.one very interesting example of a 'service' is one that's called "Summary"
just visit a webpage with a large text-body, select the whole page (command+A) and choose "Summary"
can be quite helpfull..