Já mám ve Firefoxu v liště záložek vytvořenou ikonku, kde v políčku adresa je zadané:

javascript:var%20t=((window.getSelection&&window.getSelection())||(document.getSelection&&document.getSelection())||(document.selection&&document.selection.createRange&&document.selection.createRange().text));var%20e=(document.charset||document.characterSet);if(t!=''){location.href='http://translate.google.com/translate_t?text='+t+'&hl=cs&langpair=auto|cs&tbb=1&ie='+e;}else{location.href='http://translate.google.com/translate?u='+escape(location.href)+'&hl=cs&langpair=auto|cs&tbb=1&ie='+e;};