If you've got a CLI inclination, you can use the eject command, which will unmount the device for you and (if you CDROM supports it) eject the media. Just type:
Code:
eject /dev/cdrom (or wherever your cdrom's located)
and if you want to put the CDROM back in without even touching it, just type:
Code:
eject -t /dev/cdrom
Hope that helps!