I believe the admins can utilize free css mobile/handheld code already provided by wordpress. I was actually researching this very thing and came in now to request the same result, with a different option of achieving it.
The forums don't look too bad on the iphone specifically right now, but it would be a huge improvement if they came out looking like they do in your link, but for free.
EDIT: Disregard, just saw this thread:
http://www.camaro5.com/forums/showthread.php?t=74084