"It's value in relationship to other currency."

 Globalization has made this relative relationship more fluid.  And, unfortunately, because of the lacking gold standard the values are very arbitrary.  With gold appreciating at its current rate, a transition back to a tangible standard is a very expensive proposition.  So currency is a market like any other that gets shopped for the best deal.  Countries with large stakes in foreign currency, like China, and emerging economies are likely to diversify and be less willing to finance American debt.  That can only weaken the dollar further. 

The US has trade issues and any campaign to bolster the dollar (in an attempt to promote domestic liquidity) will only make the economic correction more difficult.  The deficit is a very real issue that can't simply be written off at a later date.  We are the premier economic power in the world but the bulk of our individual wealth is built on borrowed money, and sooner or later there is a reckoning day.  I'm not a pessimist and I'm not implying that the bottom is going to fall out in Depression Era fashion.  But there is significant disparity in global economies and the relationships are diverging at an exponential rate, as are the levels of wealth in this country.  It's cliche to say that the rich get richer and the poor get poorer.  But it's certainly true, relatively speaking.  Fortunately, those who are considered poor in this country still enjoy a standard of living proportionally greater than the global average.  And, actually, that bodes well for the future of our economy.

Fundamentally, the demand for agricultural production is growing at an exponential rate similar to that of our population growth.  The crunch is now the burden developing economies are making as their appetite for energy has developed.  Genetics and farm land expansion have always allowed supply to meet growing demand.  But, wheat didn't have a great year this year and the forecast for corn consumption in ethanol is ever growing.  So debt and demand are the theme of 2007 and we are a slave to both, even though they are contrary in nature.  So my forecast is steady.  It can't go down much more and afford significant losses in foreign investment and it can't go up much more and lose exports.  That's what you get when you need to sell to countries that make all the things you need to buy.  It's a catch 22 for everybody.  Throw economic theory out here, we're already in a weather market.