What do you want to do with these zip codes?
If you simply want to get information from a zipcode, such as the state and
city, you may want to just download zipcode data from the web and import
into whatever database you use. This may be the simplest and quickest way
to search and find additional info. about a US zipcode.
The US Census webpage lets you download an assortment of US zipcode related
files. By selecting the file "Zips," you can download nearly 30,000
zipcodes from:
http://ftp.census.gov/geo/www/gazetteer/places.html
These are comma separated value files (*.csv) and can be easily imported
into most databases or spreadsheets. Note that many unincorporated
zipcodes are not included in this particular file, but there may be more
complete ones out there that can be downloaded.
This particular file also contains latitude and longitude values for these
zip codes, as well as some population information. I've used files like
this to generate maps.
Thanks,
Thomas Zimmerman
http://seeing2020.com/museums/
Museum Resource Board