I recently enabled WPTouch to change the user interface for mobile users visiting using iPhones, Android phones, Palm Pre phones and other smart devices. Hopefully this will speed up the page loads for people checking the site on the go.
WPTouch is a plugin from Brand New Code and is easy to install and use. Instead of being served the regular page, a stripped down page is shown. But just because it is stripped down doesn't mean there is a a loss of functionality. Users can still leave comments, navigate to other pages or jump to your Twitter feed.
If your site uses WPSuperCache there are a few things you will need to configure and there is help for that on the WPTouch website but other than that it works right out of the box.
You can get more information at the Brand New Code website http://www.bravenewcode.com/products/wptouch/