ruby script/plugin install http://rails-mobilecompability.googlecode.com/svn/trunk/

There are 3 methods that you can use

Test if the request is from a mobile device (returns true or false):

request_from_mobile?

Will display alt text instead of image if true:

mobile_image_tag(image, options) If request_from_mobile?

If true no stylesheet will be shown:

mobile_stylesheet_link_tag(normal_style, mobile_style = nil) If requuest_from_mobile?

There is currently no advanced documentation for this plugin.