I just updated the Mowser WordPress Mobile plugin to add an option to include a link to a handheld stylesheet when generating headers. I put up a minimal stylesheet that you can point the plugin to if you just want the default, it’s at http://pub.mowser.com/media/stylesheets/wordpress.css. Or you can copy down the stylesheet to your server, modify as you want, and change the URL to point to your own version. The difference is actually pretty pleasing, even with the simplistic stylesheet I have up now. Compare the mobile version of this blog to mobilized WordPress blog without a stylesheet at all.