The best way is to load your images like any other dynamic asset. Either use the Flash built-in loaders or an API like Bulk-Loader. Once loaded you can build your materials as needed using the bitmaps. As I understand it BitmapFileMaterial is intended as a short cut for developing or testing. Good practice is to implement a proper asset loading management.
Bulk-Loader is simple and easy and allows to load multiple images and other assets. http://code.google.com/p/bulk-loader/w/list ath. Jerome.
