CrossRoads:
Yes.
See the Learning or Playground section for accepting Serial input.
Use a relay like this to close the contacts
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=PB1110-ND
http://media.digikey.com/pdf/Catalog%20Drawings/Relays/FX2%20RELAY%20NON%20LATCHING%20FTPRNT.jpg
Connect one side of the Coil to +5V (Pin 1), the other (Pin10) to one side of a 15 ohm resister, the other side of the resister to an arduino output pin that you will drive low to energize the relay (and you may not need the resister, but start with it). Put a diode across pins 1 (cathode) and 10 (anode) to voltage spikes away from the arduino pin
(such as http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=1N4004FSTR-ND).
Connect pins 4 & 5 to your contacts.
Will this work using my relay that I bought? If not can you please explain the schematic