Maybe I'm late in noticing this, but it was a pretty handy feature so I though I would mention it.
Recently I was working with some obscure scripts that had comments written in another language. Though I had a pretty good idea what the author had intended just by reading the script logic, I wanted to see what the author's comments might have to add.
I fired up Google Translate and having traveled quite a bit I thought I would guess at what the language was. Then I noticed a choice from the drop down list that said "Detect Language" and thought to myself "Now that's a handy feature!".
I pasted my text in and hit "Translate" and Google's translate tool handily detected the source language (Dutch in this case) and spit out the English translation. Nice!