Glenn Reynolds, the Instapundit, opines on the pesky Third Amendment, and how it is is another in a string of Constitutional Amendments governments seem to ignore in their "wars" on, well, on almost everything (drugs, guns, crime, large soft drinks, buying bottled water).
This is America. A man or woman's home is their castle. If you don't have a warrant, mister tactical-costumed po-po, you must ask permission to enter. Period. Using "please" helps, y'know.