From the comments to my post on Mapping Zip And Area Code Boundaries comes a link to another, simpler site: ZipCodesMapped.Com. Type in a zip code, and get back the approximate location, area code, FIPS code, and timezone, along with a Google Maps window for the approximate area covered:

The Google Maps window isn’t always 100% accurate – the example above is for my old neighborhood, and the displayed map doesn’t cover the entire area (though it is close). While it has less information than the USNaviguide website described in the original post, for quick lookups ZipCodesMapped.Com may be more convenient to use.
Other posts in the Google Maps Tools series
- Coordinate Data From Google Maps
- Reverse Address Geocoding With Google Maps
- Converting Google Maps Search Results To GPX
- Coordinate, Elevation, Distance And More In Google Maps
- Google Maps "My Maps" Features
- Measuring Elevation, Distance And Area In Google Maps
- Creating GPS Routes In Google Maps
- Thematic Polygon Shapefile Display In Google Maps
- Using The Google Maps Interface To Display General Maps And Images
- Heat Mapping In Google Maps
- Elevation Profile In Google Maps
- Embed Google Maps "My Maps" On Your Web Page
- Customizing Google Maps Markers
- Two Fun Cartographic Google Maps Tools
- Simple Guide To Embedding Google Maps "My Maps" On Your Own Webpage
- Another Google Maps Geocoder/Reverse Geocoder
- Drawing Lines Between Points In Google Maps, Straight And Great Circle
- Convert A Google Maps Point To Multiple Text Geographic Formats
- Meet Your Friends Halfway
- Plotting Swivel Data In Google Maps
- Meet Your Friends Halfway II
- Geographic Midpoint Calculator
- GIS-Like Functionality In Google Maps With ZeeMaps
- Creating GPS Waypoints Online From The USGS Geographic Names Information System (GNIS)
- MapMyRide.com
- Exporting KML Data From Google Maps MyMaps To A GPS
- Advanced Tool For Embedding Google Maps MyMaps On Your Website
- Draw/Label On Google Maps, And Generate GPX/KML/Embeddable Maps
- Another Way To Create Embeddable Google Maps With KML Data
- Documenting A Journey With Maptales
- Plot A Coordinate Position On Different Map Pages
- Worldwide Reverse Geocoding With Google Maps
- Google Maps Shaded Relief Site Updates
- Digipoint 2: Export Of Google Maps Points In Multiple Formats, And Elevation Data
- Google Maps Line Tool Now Supports Distance Measurement
- Geographically-Linked Video With VeoGeo
- Recent Google Maps Tools
- Google Maps Mapplets From Zonums Software
- Maximize Google Maps With Google Maps Max
- Mapping Zip And Area Code Boundaries, And More
- Altitudes And Terrain Profiles In Google Maps
- “Friendly” URLs To Address Maps
- Quick Zip Code Information
- Simple Online Form For Creating An Embeddable Google Map
- Embed Synchronized Google/Microsoft Virtual Earth Maps On Your Website/Blog
- Worldwide Contour Lines In Google Maps’ Terrain View
- Plot Gazetteer Features In A Google Maps Interface
- Antipodes Map


I would recommend http://www.zipmap.info/ for any US zip code map.
You can use this to find any US zip code maps. You can search by (City,
State OR Zip). they have all the maps showing zip codes and major mile
streets in all of the united states. The service is free. Search for five
Digit Zip Code and find the Maps for all 50 states. A Free ZIP Code Finder
which can do wonders for you.
You can get the free monthly updates ZIP code database from the following URL.
http://www.zipcodeworld.com/zipcodefree.htm