such as Katie Couric, Muhammad Yunus, Olivia Wilde, Sophia Bush, Selena Gomez, and Katherine McPhee.  In addition to a musical lineup to the beat of K'Naan, Band of Horses, Black Keys, Foo Fighters, Neil Young with Crazy Horse, and John Legend, Beyonc and Hugh Jackman also made video appearances. Interspersed between the musical acts were videos introducing the "Elements of Extreme Poverty", such as Maternal Health and Polio Eradication, live tweets (#globalcitizen) as well as speakers from UNICEF, Half the Sky, Malaria No More, and other global organizations. As mentioned earlier, we were definitely in good company. However, throughout the evening, the question of what makes a global citizen floated continuously through my mind. How does one qualify or even prove his or her global citizenship?  Is it as simple as tweeting and posting several messages regarding whichever cause on your profile?  Can you simply declare that you are a global citizen and that makes you one?  Perhaps it is only a feel-good term -- wouldn't we all like a title after our names that read "Global Citizen"?  I suppose many of us are on a journey of becoming global citizens. But, how does one know when he or she has arrived? When do you get the quintessential stamp on your passport that qualifies you as a global citizen? I clearly had more questions than answers. Looking around, it seemed everyone was enjoying the music and the concert; after all, this was Foo Fighters' last concert appearance and the legendary