Script to analyze disk usage by file type.

Usage: disk_usage_by_file_type -c directory
           analyze disk usage of directory (collect data)

       disk_usage_by_file_type -s
           print disk usage by file type (uses data collected with -c)

       disk_usage_by_file_type -d file_type_pattern
           list files and sizes for a given file type pattern

See example here.