[PHP] Google Maps Distance Between UK Postcodes

[Tom Chubb]

Has anyone tried to work this out?
All I'm trying to get is the rough distance in miles between two UK
postcodes using Google Maps API for a basic auto quote script based on
mileage travelled.
I thought it would be easy but it seems that I need to convert each postcode
to Lat/Long using Geocoding and then work it out from there.
I can't find any examples so before I find another way of 'skinning the cat'
has anyone had experience of this and able to point me the right way?
TIA