Your Papers or Your Life
In May 2000, rancher Dudley Hiibel was arrested on the roadside by a Humboldt cop for refusing to show his identification, and fined $250. On March 22, the Supreme Court will hear the case. As this entertaining Hiibel-friendly website puts it:
The question before the Court is this: Did Dudley's refusal to show ID give Deputy Dove the probable cause needed to arrest him? Or is is the Constitutional right of every American to just say 'no' when asked to produce 'the papers'?
More about the defense here; there's even a video of the arrest.