Google announced the release of their official tag managing tool. Titled Google Tag Manager, the tool lets you manage tags (such as tracking and marketing optimization tags) on your site. You can add and update AdWords, Google Analytics, Floodlight and non-Google tags from the Google Tag Manager user interface instead of editing site code.
CSS (Cascading Style Sheets), a very effective thing for a site / blog these days. They give you the chance to be completely consistent with the look and feel of your pages, while giving you much more control over the layout and design than straight HTML ever did. The speed of your site also depends on your CSS, the complex the code, the slower is the site.