Mobilize.js allows web developers create mobile sites out of existing websites with little effort. It supports the following features:
Automatically detect mobile browsers.
Easy to integrate – no server side changes needed.
Open source – no expensive software or licenses needed.
Supports iPhone, Android, Blackberry, Opera Mini and other browsers and devices.
If you have a WordPress site, plugins are available for the same. To see exactly how mobile.js works, check this section of the documentation.