Harry - 3:09 pm on Feb 22, 2011 (gmt 0)
Let me rephrase. Your main site should be as mobile friendly as possible, but a single column design will limit what you can do with the layout. What's better is to offer a clean site with links to the mobile version well displayed, making it easy for users to switch, and not limiting the functionality of your main site for non mobile users. A tight balancing game is required. You want those mobile users off the main site as quickly as possible.
Not against automated redirections, but for larger devices such as tablets, they may be a problem. Tablet users don't need to be redirected. However I still believe a dedicated mobile site is required for smartphones.