My postcode finder app has appeared on the data.gov.uk website which is titled Opening up Government. The page is here http://data.gov.uk/apps/chris-hill. The only other OpenStreetMap app there seems to be Cycylestreets, so I'm in good company, but room for more neighbours.
I'm not sure about the site's title. Not so much opening up government, more releasing public data to get it used in new and imaginative ways. In my case turning dry lists of postcodes into something useful and visual.