In the August 14, 2010 Wall Street Journal, Stephen Moore describes some of the obstacles that had to be overcome in order for the Colorado Health Care Freedom Act to qualify for the November ballot. The details can be found in his piece, "Health Care Freedom Comes to Colorado".
In the August 9, 2010 Colorado Springs Gazette, Seth Richardson discusses the benefits of that initiative in his piece, "Opposing Obamacare with the 'Right to Health Care Choice' initiative".
Brian Schwartz explains why the CO initiative is not just a PR stunt. Instead, it's carefully crafted to avoid the standard objection of "a state law (or state constitutional amendment) can't trump federal law".
(First two links via StateHouseCall.)
Update: One sharp-eyed reader noted a minor inaccuracy in the Moore WSJ piece. The CO initiative does not block any federal law. Instead it blocks any state-level measures to require residents to purchase health insurance. Also, it's not yet officially on the ballot.