The coastline extractor is available as a simple input form or with a Java Map UI - Try it for yourself at http://rimmer.ngdc.noaa.gov/mgg/coast/getcoast.html

Several other coastline data products are available from NOAA including:

NOAA's Medium Resolution Digital Vector Shoreline - Compiled from hundreds of NOAA coast charts, this product comprises over 75,000 nautical miles of coastline (nearly 2.5 million vertices), representing the entire conterminous United States of America. Alaska, the Hawaiian Islands, Puerto Rico, and all other interests and territories of the United States are not included in the collection. See http://www.ngdc.noaa.gov/mgg/shorelines/noaamrdvs.html

NGDC Coastal Relief Model - This Coastal Relief Gridded database provides the first comprehensive view of the US Coastal Zone; one that extends from the coastal state boundaries to as far offshore as the NOS hydrographic data will support a continuous view of the seafloor. See http://www.ngdc.noaa.gov/mgg/coastal/coastal.html

GSHHS - A Global Self-consistent, Hierarchical, High-resolution Shoreline Database - The shorelines are constructed entirely from hierarchically arranged closed polygons. The data can be used to simplify data searches and data selections, or to study the statistical characteristics of shorelines and land-masses. Downloadble as shapefiles from http://www.ngdc.noaa.gov/mgg/shorelines/data/gshhs/

This useful resource has been around for a number of years. I recall hyping it in one of the first issues of a previous publication that I founded. The NOAA shoreline extractor is still as useful as ever... (too bad I can't say the same about the old pub!) 

http://www.ngdc.noaa.gov/mgg/shorelines/shorelines.html