This service is provided by Google. Don't complain to me about the translations... ;-)
For more information, see their FAQ. This FAQ* mainly seems to cover translating from other languages into English, but translation into the above languages also seems to work! Let me know when other languages are added etc...
This service is provided by Altavista/Bablefish/Systran. Don't complain to me about the translations... ;-)
They only translate the top 5 Kbyte of each page. See their FAQ.