I was in the process of building a web site for a friend and wanted to include a postcode look-up field with the checkout form. After doing some searching I found no sites that offered a nice way to find this info. It just so happened that the domain postcode.co.za became available during this time. Et voilà!
I waxed this little web app in a few hours and included an API for devs if they want to integrate this search feature in their own sites. The data is freely available from the South African Postal Services website and will be updated periodically. Postcode was intended to be used on mobile so a home screen shortcut was added to use this web app like you would any other app.
I consider this my own little contribution to the GovHackSA movement.