SEO Lite is a very lightweight module which will add a SEO tab to your publish page. It has an editable template that can be embedded in the header of your site. Using only one database query it should be perfect for high traffic sites.
SEO Lite has a template specified in the settings page, which can be output in the code with this tag:
{exp:seo_lite entry_id='1'}
There are several ways you can let SEO Lite know which entry is to be used on the current page. The easiest for many (using a global header file that is used everywhere) will probably be:
{exp:seo_lite use_last_segment='y'}
The above tag will fetch the last segment and use that to look up the current entry to output either entry specific meta information (if found) or the default information (if the entry didn't have any). You can find more ways of using SEO Lite in the docs.
Here's a quick video of implementing SEO Lite in an existing design (the example used is a WooThemes EE theme). Note that the video does not contain any sound.
Documentation
See full docs here
