http://wordpress.org/extend/plugins/wptouch/

The WPTouch iPhone Theme completely changes the look and feel of your site to be more native to iPhone users. It doesn’t try to fit your current theme down to the smaller screen, it simply replaces it with slick iPhone style graphics.

This is what your Wordpress blog will look like...

It also allows your users to revert back to your standard theme if they wish to.

I think this is one of the best plugins I have ever come across!! Extremely easy to use, and very effective…

Go and download it now!