Disktype

Tool for detecting the content format of a disk or disk image. It knows about common file systems, partition tables, and boot codes.
Homepage:	http://disktype.sourceforge.net/

Description

Disktype detects the content format of a disk or disk image (e.g. ISO9660, UDF, etc.). In addition it provides technical information about the image, like its size, the number of blocks, block size, etc.