Monkeybread Software is now shipping a new app for Mac users, Make Icon 1.0. make Icon is a utility designed for creating file based icons. The app features PDF file reading and QuickTime image grabbing. According to Monkeybread Software:
Monkeybread Software releases Make Icon v1.0, a utility to create file icons based on the file content. Make Icon v1.0 is made with REALbasic from REAL Software, Inc.
On Mac OS X, the application can read PDF files and use the first page to create the icon. On non-PDF files, it tries to open the file as a picture using QuickTime and takes the main image inside the file. It should work with all file types QuickTime can read, such as TIFF, JPEG, BMP, Photoshop, GIF and PNG.
You can find more information about the Make Icon release at the Monkeybread Software Web site. Make Icon is available as donationware.