mark_roach - 1:33 pm on Sep 3, 2012 (gmt 0)
I will be doing this shortly and will probably use the following approach:
Use a cookie to save the users preference for mobile or full site.
The URLs will be the same and the html generated server side will differ dependent on the value in the cookie.
There will be a link on each page to flip the value of the cookie so you can easily swap from one version to the other.