http://travel.state.gov/travel/cis_pa_tw/tw/tw_1764.html
Reproduced without the handy hotlinks ...
Current Travel WarningsTravel Warnings are issued when the State Department recommends that Americans avoid a certain country. The countries listed below are currently on that list. In addition to this list, the State Department issues Consular Information Sheets for every country of the world with information on such matters as the health conditions, crime, unusual currency or entry requirements, any areas of instability, and the location of the nearest U.S. embassy or consulate in the subject country.
Côte d'Ivoire 03/03/2006
Israel, the West Bank and Gaza 02/27/2006
Nigeria 02/17/2006
Algeria 02/15/2006
Sudan 02/06/2006
Pakistan 01/27/2006
Congo, Democratic Republic of the 01/20/2006
Colombia 01/18/2006
Afghanistan 01/09/2006
Kenya 12/30/2005
Iran 12/29/2005
Iraq 12/29/2005
Saudi Arabia 12/23/2005
Nepal 12/15/2005
Haiti 11/22/2005
Indonesia 11/18/2005
Zimbabwe 11/14/2005
Lebanon 11/07/2005
Liberia 11/04/2005
Yemen 10/28/2005
Burundi 10/19/2005
Bosnia-Herzegovina 08/01/2005
Somalia 07/21/2005
Uzbekistan 07/01/2005
Central African Republic 04/19/2005
Philippines 03/23/2005
SAFETY AND SECURITY: Americans in the United Arab Emirates should exercise a high level of security awareness.
The Department of State remains concerned about the possibility of terrorist attacks against U.S. citizens and interests throughout the world. Americans should maintain a low profile, vary routes and times for all required travel, and treat mail and packages from unfamiliar sources with caution.
In addition, U.S. citizens are urged to avoid contact with any suspicious, unfamiliar objects, and to report the presence of the objects to local authorities. Vehicles should not be left unattended, if at all possible, and should be kept locked at all times. U.S. Government personnel overseas have been advised to take the same precautions. In addition, U.S. Government facilities may temporarily close or suspend public services from time to time as necessary to review their security posture and ensure its adequacy.
Taking photographs of potentially-sensitive military or civilian sites, and/or engaging in mapping activities, especially mapping which includes the use of GPS equipment, without coordination with UAE authorities, may result in arrest, detention and/or prosecution by local authorities.
I don't think it's a good idea to book a room at the Dubai Hilton.