twitter_translate.user.js

// ==UserScript==
// @name          Twitter Translate
// @namespace     http://www.netgents.com/twitter-translate
// @description   Translate tweets in a foreign language to English
// @require       http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js
// @include       http://twitter.com/*
// ==/UserScript==

$(document).ready(function() {
  function addTranslate() {
    $("li > span.status-body > span.meta").filter(function() {
      return !$(this).hasClass("retweet-meta") && $(this).children("a.translate").length == 0;
    }).append("<a style='color:gold;font-style:italic' class='translate' href=''>translate</a>");
  }
  function setup() {
    GM_log("locale = " + navigator.language);
    var language = unsafeWindow.google.language;
    addTranslate();
    $("a[class='translate']").live("click", function(event) {
      var content = $(this).parent().prev();
      language.detect(content.text(), function(result) {
        if (!result.error && result.language) {
          language.translate(content.text(), result.language, "en", function(result) {
            content.text(result.translation);
            content.css("background-color", "yellow");
          });
        }
      });
      event.preventDefault();
      return false;
    });
    window.setInterval(addTranslate, 5000);
  }
  unsafeWindow.doneLoadingScript = function() {
    unsafeWindow.google.load("language", "1", {"callback": setup});
  }
  var script = document.createElement("script");
  script.src = "http://www.google.com/jsapi?callback=doneLoadingScript";
  script.type = "text/javascript";
  document.getElementsByTagName("head")[0].appendChild(script);
});