//The U.S. President's latest tweet... var obamaTweets = "http://www.twitter.com/status/user_timeline/BARACKOBAMA.json?count=5&callback=JSONPCallback"; jsonp.fetch(obamaTweets, function(data) {console.log(data[0].text)}); /* console logs: From the O

jsonp.js

var jsonp = {
    callbackCounter: 0,

    fetch: function(url, callback) {
        var fn = 'JSONPCallback_' + this.callbackCounter++;
        window[fn] = this.evalJSONP(callback);
        url = url.replace('=JSONPCallback', '=' + fn);

        var scriptTag = document.createElement('SCRIPT');
        scriptTag.src = url;
        document.getElementsByTagName('HEAD')[0].appendChild(scriptTag);
    },

    evalJSONP: function(callback) {
        return function(data) {
            var validJSON = false;
	    if (typeof data == "string") {
	        try {validJSON = JSON.parse(data);} catch (e) {
	            /*invalid JSON*/}
	    } else {
	        validJSON = JSON.parse(JSON.stringify(data));
                window.console && console.warn(
	            'response data was not a JSON string');
            }
            if (validJSON) {
                callback(validJSON);
            } else {
                throw("JSONP call returned invalid or empty JSON");
            }
        }
    }
}

//usage...

var obamaTweets = "http://www.twitter.com/status/user_timeline/BARACKOBAMA.json?count=5&callback=JSONPCallback";
jsonp.fetch(obamaTweets, function(data) {console.log(data[0].text)});

var reddits = "http://www.reddit.com/.json?limit=1&jsonp=JSONPCallback";
jsonp.fetch(reddits , function(data) {console.log(data.data.children[0].data.title)});