USB Flash Memory permissions

[John Talbut <john@dpets.demon.co.uk>]

I am having difficulty changing the permissions for my flash memory sticks.

As I understand it, Gnome Volume Manager, invokes pmount-hal which passes back 
settings from hal and hal gets settings from udev.  I have looked through the 
various udev rules files and anything to do with hal and I cannot work out how I 
end up with the line:

/dev/myFlash /media/usbdisk vfat 
rw,noexec,nosuid,nodev,quiet,shortname=mixed,uid=1000,gid=1000,umask=077,iocharset=utf8 
0 0

in /etc/mtab , particularly the umask=077 .  Does anyone know where this value 
comes from and hence what to change in order to change the permissions?

John