As noted interest groups sought to mobilize their activists and supporters to submit relevant questions:

Global Warming
-Navin Nayak, director of The Heat is On, a partnership project of the League of Conservation Voters Education Fund, submitted the LCV's question.

Hi.  My name's Navin.  I'm sitting on the steps of the Supreme Court, the site of many historic decisions, including one this year that I'd like to ask you about.  The Bush administration has used executive authority in unprecedented ways over the last 6 years except to address global warming.  They claimed they didn't have the authority to regulate carbon dioxide.  Well this year the Supreme Court ruled otherwise.  In other words the next president has the authority from day one to begin addressing the problem.  My question is what will you do through executive authority, without passing any laws to tackle global warming?

Hello Democratic candidates.  I've been growing concerned that global warming, the single most important issue to the snowmen of this country, is being neglected.  As president, what will you do to ensure that my son will live a full and happy life?  Thank you. (Later, addressing a possible Republican YouTube debate, former Gov. Mitt Romney said, "I think the presidency ought to be held at a higher level than having to answer questions from a snowman."  Meanwhile, Steve Grubbs, senior national advisor to former Gov. Tommy Thompson said, "We'll answer questions from any American who wants to ask one and that includes one dressed up like a snowman.")

Darfur
The question on Darfur came from three activists from Stop Genocide Now -- Gabriel Stauring, Yuen-Lin Tan, and Consuelo (Connie) Stauring -- standing behind a group of children in a refugee camp  Their question:

I'm Gabriel.  I'm Yuen-Lin.  And I'm Connie, from a refugee came near Darfur.  Before you answer this question imagine yourself the parent of one of these children.  What action do you commit to that will get these children back home to a safe Darfur and not letting it be yet another empty promise?

Other Darfur questions were submitted.  The Save Darfur Coalition encouraged questions from activists.  The group had a staff member on the ground in a refugee camp in Chad, so it filmed her asking a question to the candidates:

Hello, I'm Laurie Dundon from Oregon, and I'm standing here now in eastern Chad, home to some of the many refugees from the conflict in Darfur.  My question to the candidates is what would you do to end this ongoing crisis in Darfur, to end the suffering of these people and to prevent such atrocities in the future?

The Republican Party
-RNC chairman Mike Duncan submitted a question asking Senators Clinton and Obama about their views on a date certain for withdrawal from Iraq.  His submission garnered some media attention but was not selected.