Here's one I came up, pretty simple.

This script will lookup the MAC address of a machine on your local network as long as you know the hostname. You can also look up the MAC of the computer you're currently at by using it's hostname or "localhost"

It will also copy the MAC address to the clipboard for you. Very useful if you need to share it.

Usage (from within Powershell):

.\get_mac.ps1 <hostname of computer>

Hope this helps somebody!