Hacker News Reader

I'm not entirely sure what you're trying to accomplish, but the USPS TIGER database can (sometimes) be useful in this area: http://zip4.usps.com/ncsc/addressmgmt/tiger.htm

Here's a direct link to a CSV of the 2000 Census Fips Region/Zip code, which I believe is taken from the USPS TIGER DB:

This is awesome, it has loads of data, I can use it all, thank you

All I need is a mapping from county to cities, which is missing in this data too

this doesn't seem to have any link that gives this result