How to change LCD backlight dimness automatically on boot

[blueplastic]

Hi, I just installed Linux Mint and have a quick question about the best approach to change my laptop's dimness upon boot.

When I'm logged in as root, I can run a command like this with a number between 0 (min brightness) and 15 (max) to change the brightness:

echo 8 > /sys/class/backlight/acpi_video0/brightness

But how can I get that to run as boot without password each time I login.

If I should change the /etc/rc.local file, then what exactly should I add in there so that the command runs without prompting for password?

[blueplastic]

I'm guessing I have to add something like this to the rc.local file, but that doesn't do the trick:

echo 8 | sudo tee /sys/class/backlight/acpi_video0/brightness