Improving Jeremy Keith's CAT news example from http://24ways.org/2011/conditional-loading-for-responsive-designs

cat.js

var cat = {};

/**
 * cat.NewsBox
 * Retrieves news from Google
 */
cat.NewsBox = (function(){
    
    function NewsBox(searchTerm, injectFn) {
        this.searchTerm = searchTerm;
        this.injectFn = injectFn;
        this.dom = document.createElement('div');
    }

    NewsBox.getURL = 'http://ajax.googleapis.com/ajax/services/search/news';

    NewsBox.template = '\
        <article>\
            <a href="{unescapedUrl}">\
                <h3>{titleNoFormatting}</h3>\
            </a>\
            <p>{content}</p>\
        </article>\
    ';

    NewsBox.prototype = {
        get: function() {

            // Process JSONP request

            var me = this,
                callback = '_' + +new Date,
                script = document.createElement('script');

            script.src = NewsBox.getURL
                       + '?v=1.0&q=' + this.searchTerm
                       + '&callback=' + callback;

            window[callback] = function(data) {
                delete window[callback];
                me.populate(data.responseData.results);
            };

            document.getElementsByTagName('script')[0].appendChild(script);

        },
        populate: function(news) {

            var html = [];

            // Populate the template (tokens: `{...}`)

            for (var item, i = 0, l = news.length; i < l; ++i) {
                item = news[i];
                html[i] = NewsBox.template.replace(
                    /\{([^}]+)\}/g,
                    function($0, $1){
                        return item.hasOwnProperty($1) ? item[$1] : $0;
                    }
                );
            }

            this.dom.innerHTML = html.join('');

            this.injectFn();

        }
    };

    return NewsBox;

}());

usage.js

new cat.NewsBox('cats', function() {
    // Inject news list into the document:
    document.body.appendChild(this.dom);
});