WebPlus X6: Mobile site - sub domain or not?

Hi All,

I am just about to embark on a mobile version of my site and wanted some advice.

I will be using the built-in WebPlus conditional redirect if mobile device logic and will place the mobile site files in a sub folder called mobile on my host server.

My question is should I set-up a sub domain such as http://mobile.domainname.co.uk and point the redirection to the newly created sub domain containing the mobile files or should I point the redirection at my current domain specifying the mobile folder in the path to the files?

The mobile site will contain pretty much the same content as the 'desktop' site and I know that duplicate content rules do not apply to content in the same domain but does anyone know if this rule also applies to a sub domains?

Hope the above makes sense.

Many thanks

Steve.