I was looking for a mobile custom theme solution for WordPress and ran across this great plug in here: http://www.wp-mobilizer.com or here at wordpress.org: http://wordpress.org/plugins/wp-mobilizer/

Follow these instructions for implementing a custom theme: http://www.wp-mobilizer.com/documentation/appearance-theme-options/

Remember this line in the header.php of your theme:

[cc lang="html" tab_size="2" lines="40"]

[/cc]