How To Find Live Examples Of Sites Using Specific WordPress Theme
it's as simple as a Google search. Simply type in "wp-content/themes/[theme-name]" ,quotation marks and all, and look for a search result that looks like a PHP scripting error. Google sometimes indexes these errors which is why the name of the theme shows up in search results
or
If you wana know what Wordpress theme a current site is using, What WordPress Theme Is That? , also tells you what plugins the webmaster is running and where to purchase the theme.
Enjoy
Rudy