If there's one thing the net is lacking, or at least my is yet to get my attention, it's an efficient multi lingual dictionary. Google has it's page translator, and there are many localized dictionaries to translate from A to B, but more often than not, I find myself Googling or Wikipedia-ing the terms I want translated.
Perhaps living a bilingual life gives me more of a need for this tool than many living in the US, but TechCrunch's mention of Lingoz this evening got my attention.
I played around with some French, Spanish and Hebrew words, and it even has a cool tool to differentiate between US and UK English. Words can be broken down into categories so searching for the term "Orange" gives you options from Psychology, Computer Graphics, or even Basic Colors. Best of all, this site is powered by Babylon, a company with ten years of success behind them.
If you ask me, they're on to something good here, after all, if you need a hotel in Germany or Places to Stay in the UK, you need to know how to ask for it!