Cleaning up my reading list I feel over an article on BoingBoing on a service being asked to cease and desist http://boingboing.net/2009/10/06/royal-mail-uses-lega.html.
I am very interested in post codes so I had it bookmarked for some time, since I wanted to read it at some point.
Then on twitter I see that a fellow programmer has developed a service to lookup you post code in the UK based on location data. http://whatismypostcode.appspot.com/
I immediately wrote him with a link to the article, without reading his service disclaimer.
Apparently the data has been opened to the public, please see: http://www.ordnancesurvey.co.uk/oswebsite/opendata/
So now I know what I want for Christmas, or perhaps even sooner – I want a similar initiative in Denmark.