> I have never really messed around with files in /dev before, but I want
> to make /dev/modem usable by a group. How do I do that?
>
> crw-rw---- 1 root 14 4, 64 Feb 25 20:01 /dev/ttyS0
`chown root.modemgroup /dev/ttyS0`
`chmod g+rw /dev/ttyS0`
Just like any other system file. UNIX is a beautiful thing, no?