For my quick reference...
mkisofs rawks!!
To make an ISO from files on your hard drive, create a directory which holds the files you want. Then use the mkisofs command.-SG
mkisofs -o /tmp/cd.iso /tmp/directory/
This results in a file called cd.iso in folder /tmp which contains all the files and directories in /tmp/directory/.
For more info, see the man pages for mkisofs, losetup, and dd, or see the CD-Writing-HOWTO at http://www.tldp.org.