Connect to wwwuspscom for zip code search


I am beginning to research the ability to connect to the USPS website to download current zip codes. The USPS grants customers logon and passwords to connect to their test and production websites/data bases.
As I looked into this, it struck me that someone must have already written the code to connect and download current active zip codes.
If not, I’ll be writing something my self.
So my question is, has anyone written a zip code download program connecting to the United States Postal Service?

Thanks for feedback,
JR Smith