Change permissions on /dev file?

[Toralf Lund]

How can I update permissions on a device file on an FC4 setup? I mean, I 
know I can use chmod, of course, but the problem is that for /dev 
special files, the changes are lost on reboot.

More specifically, I have a SCSI scanner, and I (obviously) want to 
access it as a regular user, but by default /dev/sg* can be read and 
written only by root. How do I change that? (And why don't devices like 
this automatically get user accessible?)

- T