Useful (and cool) hyperlink trick

There's an editorial in the NY times which features a very interesting bit of hyperlinking:

At the bottom of the article [at http://www.nytimes.com/2007/02/13/opinion/13tue4.html?_r=1&oref=slogin] it states :

"To find reference information about the words used in this article, hold down the ALT key and click on any word, phrase or name. A new window will open with a dictionary definition or encyclopedia entry. "

Yes, ANY word. And the article text doesn't show the usual blue text or blue-underline of hyperlinking. Nor does the mouse cursor change to a pointing finger when hovering over any word in the article.