The difficulty with playing the foreign exchange markets

How can I be expected to know which currency to put my money in when the UK, the US and the Euro Zone are all screwed. My views of the broken UK economy are well known and Greece's economic collapse and the near collapse of Ireland, Portugal and Spain (the so called PIGS economies) makes the Euro Zone weak and of course with news that

"A leading credit rating service warned the United States' stellar ratings could take a hit because of the U.S. budget deficit and slow pace of economic recovery.

Moody's Investors Service issued its determination Wednesday, two days after the Obama administration said the deficit in fiscal 2010 would be about $1.6 trillion and about $1.3 trillion in 2011. The 2011 estimates work off the assumption of a relatively strong bounce for the U.S. economy. "

Maybe Japanese Yen or the Swiss Franc?