from arcscripts.esri.com:
This Python (v2.1) script will add or replace projection information for the all feature classes/shapefiles a user-specified directory based on the projection of a specified feature class/shapefile. This was possible in ArcGIS Desktop 8.3 and ArcView 3.x, but cannot be done out-of-the-box with ArcGIS Desktop 9.0.
The download also includes the BatchDefineProjection script from the Data Management Toolbox on support.esri.com and a custom ArcToolbox containing script tools for both scripts with detailed documentation.
Please use the ‘contact author’ link above to let me know if you find these tools/scripts useful, have issues with them, or have suggestions to make them better.
