http://www.grcdi.nl/linkspo.htm
http://www.usps.gov/moversnet/
http://www.royalmail.com/quick_tools/postcodes/index.asp
http://www.royalmail.com/default.htm
http://www.canadapost.ca/segment-e.asp
http://www.canadapost.ca/splash.asp
http://www.freightgate.com/resources/tools.tet
http://www.wwmerchant.com/iship/ship.asp
http://www.upu.int/post_code/en/postcodes.html
http://pbworks.valueship.com/content/RateShop.asp?ref=main03
http://dir.yahoo.com/Reference/Postal_Information
http://www.stamps.com/welcome/
http://www.uspsglobal.com/get/prod/gpm_busi/rate.htm
http://www.usps.com/cgi-bin/api/shipping_label.htm
https://sss-web.usps.com/ds/jsps/index.jsp
https://sss-web.usps.com/ds/jsps/showFaq.jsp
.
.
.
.
.