Federal agencies

http://www.usa.gov/Agencies/Federal/All_Agencies/index.shtml

OK. I've attached a link to a list of government agencies. It's a place to start.
Pick one, read up on it and comment on what it does. Why does it exist? If the agency didn't exist what would be the effect? What steps must be taken to eliminate that agency?

Is there a way to eliminate one law or rule and thereby eliminate multiple agencies?

If the 16th amendment were repealed without an alternative means of income for the U.S. government I believe a large number of the alphabet would be eliminated in one fell swoop. Not a likely occurance, but one possiblity.

Basically, the House would have to propose an amendment to the Constitution. This amendment would be discussed and voted on. Assuming that it passes to the Senate the process would be similiar, discuss and vote. When passed it would be proposed to the individual states. Each state would then go through its' own process (most similiar to the Federal level). When three fourths of the states passed the amendment it would become part of our Constitution. Easy right? Yea, right.