According to a Press Release from the Green Party of the United States, dated, July 17, 2012:
Delegates from across the US at the Green Party's 2012 National Convention nominated Jill Stein for President and Cheri Honkala for Vice President at about 4:00 pm on Saturday, July 14 in Baltimore, Md. Dr. Stein won the nomination with 193.5 out of 294 delegates' votes. Roseanne Barr received 72 votes and 17 votes were cast for Kent Mesplay.
A video with highlights of the nomination, including a morning press conference and nomination acceptance speeches by Dr. Stein and Ms. Honkala, has been posted online at: http://www.youtube.com/watch?v=h7tYwkj5qLk
The Green Party aired the entire nomination on the party's Livestream Channel: http://www.livestream.com/greenpartyus
The nomination and many other convention events, including press conferences, interviews with Green candidates, workshops, and other events, are archived on the Livestream site and also on the Green Party's home page: http://www.gp.org/.