Huge InterWiki dictionary
A few months back Patrick Hall from Blogamundo was wondering if InterWiki links could be use to produce lexicons useful for translation.
WikiWord is it. For those who wonder, InterWiki links are the links made between Wikipedia in different languages. WikiWord can translate, based on those links, but can also display the short introduction of each article as well as related terms. It's really well designed on the backend apparently. The interface needs some work to be used by our usual dude.