OK, if you trust your friend to start it and drive it for you every couple of weeks than I would go that route because it keeps the fuel from seperating in the tank and it keeps the oil from settling in the pan. If you choose to store it all the oil on the inside of the engine will settle to the lowest point it can and then if you come along in like 3 or 4months and try and start it you will have metal on metal contact. I suggest if your going to store it drain all the oil out and then when it's time to start it again pull the drain plug and run a few quarts of oil through the crankcase to lube as many moving parts as possible to prevent unecessary wear on moving parts. I do that same thing whenever I do an oil change, I drain the old oil, then i take like 2 quarts of fresh oil and let it run through and drain out the bottom so as to flush any old oil or contaminants out of the engine. Another thing is if you decide to store it, like I said only about a 1/4 tank of fuel but when time comes to start and run it again, while it's still in storage take a couple 5 gallon cans of fuel and dump it in the tank, this will stir up the remaining fuel so you don't clog any injectors with anything that may have settled in the bottom of the tank. Hope all this made sense, good luck whatever you decide to do.
P.S.-Or you could just leave it at my house, I'll start it and run and tear the tires off once a week for a small fee...LOL j/k