A friend of mine wanted directions for ironing a patch on a jacket translated from French to English. She went to Babblefish, and this was the result:

"To place the piece on the part has patch, rating shining underneath. To push iron strongly on the piece during 30 seconds without displacing it (to count slowly until has 30) and to proceed from grandma on the back, also during 30 seconds."

I think that's my new favorite screwed up translation. Previously it was a sign on the road leading to the fisherman's cooperative in Tulum, Mexico, which read:

"Don't litter garbage, person who is suprised littering garbage will be finded by the local authorities."