i just stumbled on something completely by chance on the ny times site. im not sure if the features always been there and id just never stumbled on it (honestly wouldnt surprise me), but if you double-click any word in an article (click-highlight), it automatically brings up a definition of the word in a new window. whoa fun! now i know what copacetic means!
har i just noticed at the bottom of the page the following:
Tips
To find reference information about the words used in this article, double-click on any word, phrase or name. A new window will open with a dictionary definition or encyclopedia entry.
i wonder how long thats been there...doh!
I have a Firefox extension that does something similar.
Highlight a word/double click/move mouse cursor over the little dictionary icon that comes up/a screen will popup with the definition.
Its not as intuitive as it could be, so I haven't gotten as much use out of it.
it's had that for a while.