HOWTO Create ISO on Mac OS X

Found here:

1. Insert CD/DVD source

2. Fire up a Terminal, you can then determine the device that is you CD/DVD drive using the following command:


$ drutil status
Vendor Product Rev
MATSHITA DVD-R UJ-835E GAND

       Type: DVD-ROM              Name: /dev/disk1
  Cur Write:    8x DVD          Sessions: 1
  Max Write:    8x DVD            Tracks: 1

Overwritable: 00:00:00 blocks: 0 / 0.00MB / 0.00MiB
Space Free: 00:00:00 blocks: 0 / 0.00MB / 0.00MiB
Space Used: 364:08:27 blocks: 1638627 / 3.36GB / 3.13GiB
Writability:
Book Type: DVD-ROM


1. Unmount the disk with the following command:


$ diskutil unmountDisk /dev/disk1
Disk /dev/disk1 unmounted


1. Create the ISO file with the dd utility (may take some time):


$ dd if=/dev/disk1 of=file.iso bs=2048


1. Test the ISO image by mounting the new file (or open with Finder):


$ hdid file.iso


1. The ISO image can then be burnt to a blank CD/DVD.