It took me much time to find on Obama's site that he is coming to Greensboro on 3/26. For most events, "tickets" can be ordered online, and they are free. Registration is required on the site's "events" page:
http://my.barackobama.com/page/event/myevents_login
I know his campaign considers Obama to be a "shoe in" victor for the nomination fight, but the ticketing and registration requirements remind me of another recent political campaign's policies. Why would Obama want to also have such a regimented image?