All jokes aside, I looked at the S&P 500 for the period from March, 2009 to January, 2010. I made all kinds of calculations of the kinds of profits I could have captured with various methods with 5 to 6 trades, 12 to 15 trades, many, many trades and one single trade. Believe it or not, the one that would have profited more would have been to buy an out of the money option on SPY and just hold it for that entire time.
I wouldn't encourage blind investment, but in Mastering the Trade by John Carter, he said some people will put $20,000 in two currency accounts, one long, one short on the same currency and just wait six months. One account will have a blowout with the other account growing to $400,000.
I just read on Bloomberg that Greece is not out of the woods yet, but given the kind of pessimism that's out there currently, maybe the euro DOES have some potential to move up (even if it crashes in six months, we don't know yet).