My homepage goes mobile :-) templates is not yet optimized, but your feedback is as always welcomed!

From Mobile Sites with Joomla! CMS

As the number of mobile devices continues to outpace the number of desktop computers, the creation of mobile-accessible sites is becoming more and more important. This article addresses the issue of making a Joomla based site mobile-accessible.

For other content management systems such as Typo3, Wordpress, and Drupal, the making of mobile-friendly versions of the sites has already been discussed on mobiForge (see Multi-client Websites with the Typo3 CMS and WURFL, Mobile-Friendly Blogging with WordPress, and Creating Mobile Sites in Drupal Using Multisites). This article is devoted to achieving a similar effect in Joomla using the 'PDA-mambot'.

And

Creating Mobile Websites with Joomla 1.5

I also want to point out some very handy web applications, the first one is to measure how currently your site is performing while in mobile mode:

http://ready.mobi/launch.jsp?locale=en_EN

While the other are more for testing the result of your hard work:

waltercedric.iphone http://www.testiphone.com/
This is a web browser based simulator for quickly testing your iPhone Applications. This tool has been so far tested and working using Internet Explorer 7, FireFox 2 and Safari 3 in Windows, but you need Safari to get the real
waltercedric.opera.mobile http://www.opera.com/mini/demo/
A live demo of Opera Mini that functions like it would when installed on a handset (Java Applet)
waltercedric.android.mobile To test on Android, there is a bit much more effort: you'll have to download a simulator (in fact the full sdk) and launch sdk\tools\emulator.exe

To test the result in ANY browser with none of the above, just append to your site index.php?tp=1&template=pda like

http://www.waltercedric.com/index.php?tp=1&template=pda