There's a change theme option at the bottom of the thread page.
That too.

(I was going to suggest changing the useragent string to match the Iphone, but you can change the them to Mobile or default with the link below.)
** Greasemonkey would allow you to keep the warrior theme ~minus the background image.
There is also http://www.zenimax.com/external.php?locale=en-us&url=http://www.userscripts.org to peruse.