Why can't we de-value the US dollar vs. other currency ?

Seems to me that if we de-value the US dollar, we will buy less from foreign country and other country will buy more of our goods.
That should solve the problem of trade deficits and out sourcing of US jobs to other countries.

Is it because of the oil dependancy that stop us from doing it ?

apparently the value of the dollar in comparison to the euro and the yen is at its all time low. the reason why a lot of american companies are now being bought by japanese, european and arab firms. as the dollar loses its value, so does other currencies of developing countries. outsourcing of labor will not be solved by the devaluation of the dollar.

The short answer to your question is: devaluation of the dollar is called inflation. A house would cost more even though it is not imported. There will still be a demand for oil with cheaper dollars. The world market trades oil with dollars. To selectively punish consumption of oil would be accomplished by adding US tax -- something that has worked with cigarettes.

The government is currently running an experiment called Free World Markets. Everyone has to suffer for the next 40 years until they sort out which country will offer what goods and services.