Usage:
  http://www.theagricolas.org/craig/zip4.php?<address>,<zip4>
  http://www.theagricolas.org/craig/zip4.php?<address>,<city>,<state>

  <address>, <zip4>, <city>, and <state> should be URL encoded

  This works well as a Firefox/Mozilla macro or as a YubNub command.
  For both, the URL would be "http://www.theagricolas.org/craig/zip4.php?%s".  On YubNub, this already
  exists as the "zip4" command.

Examples:
  http://www.theagricolas.org/craig/zip4.php?1600+Ampitheatre+Pkwy,+Mountain+View,+CA
  http://www.theagricolas.org/craig/zip4.php?701+First+Avenue,94089

  Note that the URL encoding is fine with %20 as space (instead of '+') and
  %2C as the comma (',').

This meager script copyright (c)2006 Craig B. Agricola <craig@theagricolas.org>
All it does is rewrite your URL for you; I take absolutely no credit for the
data that is returned; that's all the US Postal Service.