Best way to do postcode to postcode calculations for a website?

[MuGeN]

From what I've read, to use the royal mail as a source for this info is crazy money... could anyone recommend a decent non-ripoff way to stick 2 postcodes in and get a distance out?

I would have thought theres a way to reference Google Maps which would actually be better since it could do road distance instead of crow-flies? Any ideas?

 

[Dj_Jestar]

You've already hit the nail on the head.. Google Maps..

 

[Tilluss]

http://code.google.com/apis/maps/