Google has announced a WordPress site verification plugin that is said to simplify the process of verifying your ownership of a site, by making calls to the Google Site Verification API to automate the entire verification process. giving you faster access to a variety of Google services. Including adding a site to Google Webmaster Tools or using some features of AdSense, Merchant Center, Sidewiki and more.
This plugin needs WordPress 3.0 (or higher), PHP 5.2.0 (or higher), the JSON PHP extensions, and the CURL PHP extensions. The plugin won’t activate if these requirements aren’t met.
Download: http://wordpress.org/extend/plugins/official-google-site-verification-plugin/