Currently private citizens in 20 States have filed with the US Government to allow their States to Secede. You can go here to see them.
Now, I don't think any of these petitions will be granted. Among other things, I would think such requests would have to come from the Governments in those States. On the other hand, I think it is very important to sign the petition for your State if there is one, and create one if there is not.
Our Nation has ceased operating within the bounds of its own Constitution. This began with the Civil War when States were denied the right to secede (a right they had been assumed to have from the beginning of the Nation). Now, I'm not going to re-fight the Civil War, here, and I think it was (generally) a good thing that it went as it did, but we cannot deny that the Civil War was the first body-blow against the Republic. It continued from there with great leaps forward during the Great Depression and FDR's New Deal, and again under Jimmy Carter and the "Great Society." Today, the Union little resembles that Republic of Sovereign States designed in Philadelphia in the late 1700s. When ObamaCare goes fully into effect, it won't matter what our nation claims it is, it will actually be a tyrannical oligarchy wherein the Political Class rules over the rest of us. In many ways it is already there, but once the Government is allowed to make direct decisions regarding your health and life, you are no longer a citizen, but a subject.
As such, it is of vital importance to let both Washington, DC, and our own States know how we feel about this. The politicians must be made to see how deeply we believe in our Liberty, and the lengths we are willing to go to preserve it. If we are to repair our Republic, we must start by shaking the politicians' belief that we'll just go along with whatever they decide. We must also make it real in our own minds what we are asking, and what price we are willing to pay for it.