Mobile support best practice

How best to structure a website for PDAs

[scooby2]

Am about to build PDA versions of a couple of my sites and would appreciate some opinions on the following.

sub-domain or sub-directory - pros and cons of pda.foo.com versus www.foo.com/pda/ selectable by a link in the top-left.

dupe content - intend to use Google's Mobile Sitemaps but how to avoid dupe content issues with the web / pda pages having similarities (although the page structure and xhtml will be quite different)?

...and anything else I may not have thought of... (;^)

Many thanks,
Scooby

[cerebrum]

Wait man. .mobi is being rolled out in this month.

Then you can launch foo.mobi