I've heard some good things about WPTouch for WordPress so sites are displayed well on mobile devices. I am wondering if I am using a WP theme that is 'responsive', then does that mean it does everything WPTouch does? Are there some things that WPTouch does that my responsive theme would not do and so I should always activate WPTouch?
I prefer responsive design to mobile-exclusive layouts, because with responsive design you can make sure your layout works on ALL devices---plus, some phones and tablets have giant screens, and I wouldn't want to serve them a "mobile version" of my site.
The only upside about using alternative versions of the site for mobile devices is that you have more control over what content is displayed. Sometimes, if you have a larger site, you'll want to simplify it a bit for mobile users (but never hide essential content)
I haven't tried WPTouch, but yeah, I've heard some good things about it.