Whats wrong with simply dragging the cursor over the word, Ctrl-C to copy, Ctrl-T for a new tab, then right-click and Paste to insert into the Search box (I use ixquick) and Enter to perform the search? Very fast and no need to add another extension/addon?
Works quite well in Opera.
Nothing wrong with it. This is a way to put together a collection of search resources easily accessed with highlight and two clicks. No more, no less.