amazon has a few cheap relay types my favorite is http://www.amazon.com/SainSmart-4-Channel-Relay-Module-Arduino/dp/B0057OC5O8/ref=sr_1_16?ie=UTF8&qid=1332943785&sr=8-16 5v power relay, with 4 inputs. The are reverse logic I beleive, So low is On and High is Off little red light will show so.