Set preferred domain for Google Webmaster Tools

Adding this website to Google Webmaster Tools just presented me with a small but annoying problem of not being able to set the preferred domain to contain www. rather than just adamkdean.co.uk. I received an error message, but no instruction on how to do so:

Part of the process of setting a preferred domain is to verify that you own http://adamkdean.co.uk/. Please verify http://adamkdean.co.uk/.

I tried to visit the verification file using no www. but no dice. I also tried adding the website as the root domain, adamkdean.co.uk, but still no luck.

It turns out you have to add the website twice, both with and without the www subdomain, so two entries in your webmaster tools, and two verification steps.

Could have thrown me a bone, Google!