Windows – Command line way to change time and timezone in vista/2008

A little known one is

getmac

It shows the MAC address(es) of your network adapter(s).

The commands dig and host should be what you're looking for ;)

On *nix systems, you can use this command:

dig -x [address]

Alternatively, you can add +short at the end of the dig command to output only the DNS result.

There's also nslookup on both *nix and Windows systems for reverse DNS requests.