Here are step by step instructions on how to create an ISO from a CD or DVD in Mac OS X.

First, insert the CD/DVD and open terminal.

Type in:

drutil status

Your results may vary, here is what I see.

Last login: Mon Nov 10 09:45:51 on console
JBMac:~ John$ drutil status
 Vendor   Product           Rev
 MATSHITA DVD-R   UJ-857E   ZA0E

         Type: CD-ROM               Name: /dev/disk1
     Sessions: 1                  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:   05:10:14     blocks:    23264 /  47.64MB /  45.44MiB
  Writability:

JBMac:~ John$

The part we are interested in is Name: /dev/disk1
If your drive is not /dev/disk1, you will need to use your drive’s name.

We now need to unmount the drive, this is done by typing:

diskutil unmountDisk /dev/disk1

You should see something like:

JBMac:~ John$ diskutil unmountDisk /dev/disk1
Unmount of all volumes on disk1 was successful
JBMac:~ John$ 

Now all we need to do is create the iso file. To do this we use the utility dd.

dd if=/dev/disk1 of=outputfile.iso bs=2048

Depending on the size of the disk, this may take some time. Once complete, you should see something along the lines of.

JBMac:~ John$ dd if=/dev/disk1 of=outputfile.iso bs=2048
26717+1 records in
26717+1 records out
54716928 bytes transferred in 60.473826 secs (904803 bytes/sec)
JBMac:~ John$

And your ISO file should be created. Test it with finder or using hdid in the terminal