Programing a 8 channel relay board and IPAD App Help !

I Bought this App for the I Pad to control a relay board using a Ethernet Shield .
and downloaded his sketch to get started.
I have the IP address to the shield and the IPad
but I don't have the MAC Address of the shield to put in the sketch.
Can I just put any Letters and Numbers in there?

Does anybody have a sketch to control a 8 channel relay board that would work with this?
Just to turn the relays on and off is all , no fancy blinking or anything.
I am just staring out with Arduino and trying to learn the programming.
I Have bought a Arduino Mega Board, a Mega Compatible Ethernet Shield, and a 8 relay module.
Any Ideas anybody to get me started?

Generally, you should have had a sticker with a mac address on your ethernet shield. However, you can pretty much make one up - you would have to be staggeringly unlucky to see a conflict on your network. Don't use the same number on two shields though if they're going to both be on your LAN.

Here's an address from the ethernet library example that you could use:

byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };