Jury nullification is not only a right of a juror, it's also your duty as one. No judge today will ever instruct a jury of this right like they used to, they don't have to (supreme court ruling). But it is still a valid law that even predates the US constitution. Alcohol probation was greatly defeated due to juries exercising there rights to nullification.

I am a supporter of the "Fully Informed Jury Association" and have done a few flier handouts outside the court house of Cambridge, MA. Check out the site, Fully Informed Jury Association