Thanks for the fast response. I like the idea of simplicity but there is an issue with your suggestion.
Best practices for mobile site design is to always give the user an option of viewing the "Full HTML" version of your site.
In code you provided, the user will always be stuck perpetually on the mobile version because of the user-agent identification will not change.
This is why is beneficial to check against a cookie, if "mobile=0", then dont apply a redirect rule.
Would love to hear some more suggestions.