The Fully Informed Jury Association’s Web site starts with this quote (as of today):
The primary function of the independent juror is not, as many think, to dispense punishment to fellow citizens accused of breaking various laws, but rather to protect fellow citizens from tyrannical abuses of power by government.
The Constitution guarantees you the right to trial by jury. This means that government must bring its case before a jury of The People if government wants to deprive any person of life, liberty, or property. Jurors can say no to government tyranny by refusing to convict.
You’ll find a library of information, including legal precedents and links to other sites on the concept of jury nullification. It sounds dry, and it can be, but on the other hand, it’s also solid, and has the potential to empower average citizens.