The quickest way to mobilize your Wordpress blog is to install a plugin called Wordpress Mobile Edition. The advantage of using this plugin is that it's quick and easy to setup and it handles a lot of mobile browsers, as well as touch browsers (for Smart Phones).
However, it does have 2 substantial shortcomings:
- It doesn't scale the images to your phone's screen size (the images are usually too big to fit).
- It's hard to customize.
If your blog has a certain style that you want to maintain, it would be ideal if the mobilized version of your blog reflects your brand. WPTouch, a free plugin, can help because it scales images correctly and you can customize it. For example, I installed Version 1.9.13, manually edited the CSS and this is what I came up with.