Google will translate but the translations are very literal and often end up making you look rather silly. Best to learn the language, or get a phrase book or a very good bilingual dictionary.
this one is not too bad. But remember that any computer translation may not be able to provide the exact context of your entry, and if it has a problem it may simply translate some of the words. Tip - keep it clear and simple.
Babelfish (as recommended by Postdog) is my favourite translation site for the more common languages.
For languages that Babelfish doesn't handle (e.g. Hungarian), InterTran is quite good but it often returns 'server busy' messages: http://www.tranexp.com