Not sure what you meant by this.
But, I am sure William Penn's jury did not consider jury nullification just talk. They spent a few days in jail in defiance of judges' orders to convict Penn of preaching as a non-Anglican.
Recently in (Montana?) so many in the jury pool were opposed to a drug charge, the state could not seat a jury! The charge was nullified
before the trial started.
Lysander Spooner would not consider nullification just talk. Hunt up his essay
An Essay on the Trial by Jury, also linked earlier in this thread in one of my posts.
Also, hunt up FIJA (Fully Informed Jury Association), also linked earlier. Jury nullification does come up from time to time, if for no other reason than judges lying and telling jurors the verdict they must render if the think the accused broke the law. Some have been threatened for informing jurors of their rights and powers. If the judge or prosecutor finds you are willing to nullify even generally, they may try to exclude you. The government really,
really hates the power to nullify. And, will go to a fair amount of trouble to make sure potential jurors don't find out about it.
And, finally, do you all remember the 5th Amendment video by the law school professor? Prof. James Duane. He would not consider jury nullification just talk. He seems to have written part of a pamphlet used by FIJA:
http://www.fija.org/docs/JG_Jurors_Handbook.pdf