A contemporary example which springs to mind is that of the Tea Party, a neoconservative fringe group whose Fox News-inspired antics and protests have garnered considerable media coverage in recent months. Touting picket signs whose slogans question President Obama's nationality and oftentimes seem to encourage a violent takeover ("taking back") of the federal government, these "activists" have been successful in swaying many Republican congresspeople into blocking progress on the health care reform bills endorsed by progressives.
While these people have certainly become a thorn in the sides of our Democratic leaders, is their resistance and protestation the kind which Thoreau intended? I would argue that it isn't, because these activists are still working within the system. As I interpret it, "resistance to civil government" entails removing one's self entirely from the system, escaping the forms of governance you see as repressive in favor of an alternative all your own. You reject government, reject authority, reject the machine and instead adopt a personal system of ethical standards by which to govern one's self.
Much like the civil rights protesters in the 1960s and the gay rights activists today, one must remove one's self from the system, remove one's self from the law and live the way you believe is just, live by the self-imposed laws you find fairest. In this way I believe the spirit of Thoreau's resistance lives on through those protesters and demonstrators who fight for equal rights for homosexuals. The essence of his ideas is there: that the protest exists firstly in one's mind, and is not bound by the traditional avenues of political discourse. M.