Use of a plug-in or theme to provide a mobile version of an existing WP site

Hello,

I am currently running a site using WordPress 3.0.5. I would like to provide a mobile version of this site to viewers who are using smartphones. What is the best way to approach this? Since the site is very graphically rich, I think the best approach is to install a Mobile detector plug-in (any recommendations?), and then setup a new mobile theme (any recommendations on this also?) in addition to the existing desktop oriented theme.

I have also seen some themes that advertise themselves as Mobile friendly. Are those simply just a single theme which detects the device/browsers and optimizes the existing elements/date for best viewing, as opposed to having a separate design/images for the desktop vs. mobile scenarios?

Any thoughts/tips on this would be greatly appreciated.

Cheers,

-f.