This is a d3.js visualization of US zip codes.
Original zip code dataset from Geocommons.
5MB shapefile with properties such as zipcode, state, name, population, area, more.
http://geocommons.com/overlays/54893 (Thank you Bill Greer)
This converts it nicely:
topojson \ -p name=PO_NAME \ -p zip=ZIP \ -p state=STATE \ -o zips_us_topo.json \ zip_codes_for_the_usa.shp
Hi Jeffriesen, Thank you so much for the helpful code. Do you have any tips for how to create a .shp / .json file for a single state while keeping the zip codes as a property? I tried topojson ... -p ZIP, but I think it failed because I haven't found a proper California .shp file that includes zip code information. The zipcodes_for_the_usa file is great, but I only want California. Thanks!