WordPress.org

Install the Mobilize by Mippin plugin by unzipping and copying the file called mobilize-wordpress-plugin.v.1.4.php into the /[wordpress data root[/wp-content/plugins/mobilize-wordpress-plugin.v.1.4.php.

Then restart your apache server. If you click the Plugins tab on the admin dashboard you will see an entry called "Mobilize by Mippin Wordpress Plugin". Click on "Activate" on the right to start the plugin working. Then all phones coming to your site will get a mobilized version whilst PCs continue to get the existing rendering.

To test this try using an operamini demo (be patient as it takes some time to load initially)

http://www.operamini.com/demo/

then try you url on PC browser and check it still displays your blog. That's it.