Here's mine:

"Please order the FBI, CIA, Pentagon, FAA, Secret Service, NSA and all other involved federal agencies to fully comply with the 9/11 Commission's mandate to declassify and release its records in 2009. http://www.archives.gov/research/9-11-commission/"
http://change.gov/page/content/openforquestions_20081217_private_url

I searched 9/11 and went thru the list; here's some of the better ones getting the most votes:

Dione- ""Will the many crimes committed by the outgoing administration, including the torture and rendition of detainees, the illegal war on Iraq; 9/11 conspiracy, stolen elections and likely recent murder of Rove's IT Guru, Mike Connell, be investigated?""
http://change.gov/page/content/openforquestions_20081217_private_url

Politicalboi- "Will there be a full independent investigation of 9/11."
http://change.gov/page/content/openforquestions_20081217_private_url

RPDX- "With your administration's new "transparency" policy, why not declassify all the documents pertaining to controversial debates such as the events at Roswell, the JFK assassination, and the 9/11 attacks?"
http://change.gov/page/content/openforquestions_20081217_private_url

staytrue- "NY Post, 9/13/01 "Beyond Pearl Harbor" - Rob D. Novak Security experts and airline offic'ls agree privately that the simultaneous hijacking of 4 jetliners was an "inside job," probably indicating complicity beyond malfeasance. Will Obama review 9/11?"
http://change.gov/page/content/openforquestions_20081217_private_url

Jim Lunsford- "Will we have a free and independent public investigation of the 9/11 attacks?"
http://change.gov/page/content/openforquestions_20081217_private_url