There are lots of tools available out there to translate things and students usually choose the most desperately inaccurate one when trying to take a shortcut on their homework, so it’s not hard to spot! But, used sensibly, these tools can be useful: I have written before about the really very useful Lingro, and Germanists have the brilliant Dict.cc.
But it’s worth mentioning Microsoft’s entry into the fray with the translation facility in Word 2007. It’s far from brilliant but it’s a start, I suppose, and could be useful as a way of working within a document without going out to external tools. To turn on the facility, you go to the Review tab on the ribbon and select Translation (fourth from the left). This pulls up a vertical window on the right of your document within which you can select your languages to translate from and into. After that, if you click within any word then right click and choose Translate then Translate again (why twice??) your translation will come up on the right hand side.
It is limited but it is functional. There is also an option to translate an entire text, but that is as dire as they come and only worth doing if you want a laugh! There is also an option called Translation Screen Tips, which is meant to provide a translation when you hover over a word. I’ve never got it to work in either Vista or Windows 7. If anyone has managed to pull off this trick, do let me know!