Started using a tool with Firefox this morning that I came across yesterday: the WordChamp Firefox Toolbar for instant translation of words while browsing any web page.
It is a really cool tool! You not only get to hover over any text word and get a translation into the language of your choice, often there is an audio recording of the word that you can listen to! Here's a screenshot of it in action - click to see a larger version:
To get the extension, visit WordChamp and look on the left side almost on the bottom where it says: "WordChamp Language Toolbar for Firefox". Click that while browsing the site with Firefox and you'll install the extension and can start using it once you restart Firefox.
A proper article on WordChamp will be out soon on the front page.