The Accessibility Module allows hand-held devices access to a correctly formatted web site specifically made for mobile browsers from one code base. This means that the site owner does not need to create separate versions of the site.
With basic device detection this module selects the correct "theme" to use and generates content accordingly. The content is also broken down into smaller chunks making download on a phone, for example, faster and the site should be easier to use.
Content can also be limited by role with the help of taxonomy_access module.
Please note that the themes need to exist: (web/wap/mobi) and modifications to
page.tpl.php and template.php. Demo themes are available here.
Also requires slight modification to common.inc include file, there is no patch yet but instructions can be found here.