Espresso machine mod

Hello,

I'm just getting started with Arduino and electronics stuff overall. I'm a programmer and have never dabbled with hardware at all. My goal is to try to duplicate this: http://www.arduino.cc/playground/Main/BarebonesPIDForEspresso. I think I have all of the hardware picked out but now I just don't know how to power it. It seems like it would make sense to tap into the machine's power but I don't know how to do that, and I also don't know if a little extra draw from the Arduino would make the espresso machine unhappy. But assuming it won't hurt the espresso machine, how do I go about stealing a little bit of its power and feeding it to my Arduino?

Thanks, Mark