How can I grab a users profile image using the twitter api (js)?

Question

Is there an easy way to grab a users twitter image with a simple line such as:

http://www.twitter.com/USERID/picture

If there isn't, what could I possibly look into that has an easy method to grab the user profile image?

Answer 1

UPDATE February 2014: The original answer no longer works now v1 of Twitters API has been retired. The below is the nearest substitute for what was asked, but for v1.1 of the API.

---

Version 1 of the Twitter API allowed you to do this easily, using a URL such as http://api.twitter.com/1/users/profile_image/:screen_name.format however that was retired in May 2013.

As of Verson 1.1, you cannot get a users profile picture URL without making an authenticated call . Once you have got an authenticated user, simply make a request to any endpoint which returns a users information ( such as /user/show ), and use the "profile_image_url";

jQuery.ajax('/users/show', {
    data: {
        screen_name: 'mattlunn'
    },
    headers: {
        // All your OAUTH headers
    }
}).done(function (res) {
    var url = res.profile_image_url;
    var img = document.createElement("img");

    alert("URL is '" + url + "'");

    img.src = url;
    document.body.appendChild(img);   
});