The Sixth Amendment is our Founding Fathers' attempt to make sure that the government cannot just "disappear" people, the way the Guatemalan Mano Blanco was alleged to do on a regular basis, and the way the British Officers would snatch Colonial protestors and keep them under lock and key until they got damned good and ready to hold a trial, usually with witnesses who weren't identified and with his family and friends given no clue that the trial was going to be held (or even where, for that matter), so very little chance for the defendant (some poor schmuck who may have griped about high taxes after a few too many mugs of ale) to get away. It was also a "guilty until proven innocent" sort of situation.
The Sixth Amendment reads: "In all criminal prosecutions, the accused shall enjoy the right to a speedy and public trial, by an impartial jury of the State and district wherein the crime shall have been committed, which district shall have previously ascertained by law, and to be informed of the nature and cause of the accusation; to be confronted with the witnesses against him; to have compulsary process for obtaining witnesses in his favor; and to have the Assistance of Counsel for his defence."
Can you imagine how differently our legal system would have turned out had these rights not been enumerated the way they were?
The 1963 case of Miranda v. Arizona (decided by the US Supreme Court in 1966) has established that each suspect must be read his most obvious Constitutional rights: "You have the right to remain silent. Anything you say can and will be used against you in a court of law. You have the right to be speak to an attorney, and to have an attorney present during any questioning. If you cannot afford a lawyer, one will be provided for you at government expense."
This is not to say that you cannot be arrested without the Miranda warning, just that they have to tell you of these rights before they can legally ask any questions. It also doesn't cover simple identifying information, such as name, address, Social Security number, etc. However, a case of a man who was giving information to the police without benefit of Miranda is expected to go before the Nine Brethren later this year, which might rule in such a way as to limit the usage of Miranda where the information being given isn't being used at trial against the one giving the information.
We shall see what becomes of this, since the U.S. Justice Department has already filed an amicus curia ("friend of the court") brief, explaining the official Bush Administration's position on this case. Not telling the Supremes how to rule, mind you, just how the President and his legal staff would prefer the law to be interpreted...
Non Sequitur aside (or maybe it does "sequite"?), I wonder how long Chief Justice Rehnquist will wait before deciding to retire. He was appointed as an Associate Justice in 1971 by President Nixon, and when (then-)Chief Justice Burger retired in 1986, he was promoted to Chief Justice by President Reagan. I'm sure he was hanging on until Clinton was out of office, but now that the Republicans have the White House, the Senate, and the House, he'll probably retire fairly soon. After all, he is 79 years old, and he's been on the Court for 32 years now...