Most of recent distro now use "udev" to manage /dev directory. It's like a "dynamicly generated" /dev folder, just like /proc or /sys.
It's possible to tell udevd to set special permission for certain devices at boot time, look in /etc/udev/rules.d
KERNEL="hdc", NAME="%k",GROUP="cdrw" MODE="0664"
will set permission to "664" and the group to "cdrw" for this device.
Note,of course, all this only work if your distribution use udev. Otherwise, you could just add a your chmod line to some bootup script to make sure this is done when you reboot. Or you could give your own script special root priviledge?