When the judge asked if prospective jurors would obey the rules of the court in judging the case, I raised my hand and said I wouldn't convict on the charge, regardless of the law. (Among other things, California's overcrowded prisons have repeatedly been found to be un-Constitutional.) I was dismissed from the jury.
Keep in mind that when you practice jury nullification you are committing an act of judicial terrorism. You are refusing to recognize the established rules, and you are not empowered to change them.:| :| :| :| :|