UK Postcode validation and location

 Geo::Postcode will accept full or partial UK postcodes, validate them against
 the official spec, separate them into their significant parts, translate them
 into map references or co-ordinates and calculate distances between them.
 .
 The last two features require a postcode database to be supplied separately.
 .
 It does not check whether the supplied postcode exists: only whether it is
 well-formed according to British Standard 7666, which you can find here:
 .
 http://www.govtalk.gov.uk/gdsc/html/frames/PostCode.htm
 .
 Geo::Postcode will also work with partial codes, ie areas, districts and
 sectors. They won't validate, but you can test them for legitimacy with a
 call to valid_fragment, and you can still turn them into grid references.
 .
 To work with US zipcodes, you need Geo::Postalcode instead.