I agree; the swearing-in is the best (and last) place to stop this Constitutional abomination.
I'm not one to give the opposition ideas, but, if there is, indeed, something profoundly embarrassing in BHO's (otherwise valid) Hawiian birth certificaate, if it does, indeed exist, simply sharing it with one person (Roberts) in confidence would solve the problem.
Otherwise, at the swearing-in, Roberts should simply state:
"As Chief Justice of the Supreme Court of the United States of America, I have sworn a sacred oath to uphold and defend the Constitution of the United States. This candidate, Barack Hussein Obama, has not demonstrated that he meets all Constitutional requirements for attaining the Presidency. Therefore, it is impossible for any American to render to him the oath of office, and it is impossible for him to honestly and truthfully execute that oath.These inauguration proceedings are hereby terminated."
Then the incumbent President would be forced to declare martial law and call out the full force of the military services to quell the violent coup d' etat attempt that would erupt.
Besides Roberts, how about the electors? They are also sworn to uphold the Constitution - and therefore, should verify Obama’s eligibility before they cast their votes.