Airline Regulations: 3-1-1 for Carry-Ons and Packing Tips for Carry-on and Checked Luggage. See also the TSA (Transportation Security Administration) blog for more travel-related details.

Aviation Safety Network
Descriptions of airliner, military transport category aircraft, and corporate jet aircraft safety occurrences since 1943.

AVOIDDELAYS (National Air Traffic Controllers Association)
Highlights airports with the most delayed departures, the worst times to fly, and the most delayed flights.

Bureau of Transportation Statistics

Currency Converter
Yahoo! Finance

Customs, Immunization and Passports
GPO Pathway Services Browse Topic

Foreign Per Diem Allowances

Office of Travel and Tourism Industries
Statistics, reports, and marketing opportunities for outbound travel to foreign countries and inbound travel to the United States.

Passports and Travel Abroad
Federal Citizen Information Center

Passport, Visa, and International Travel Information (U.S. Department of State)

Recreation.gov
Plan trips and make reservations for federal recreation sites.

Stat-USA | includes Full Text. No account or password necessary.
Stat-USA provides both indexing and fulltext access to economic, business and international trade information produced by the U.S. Government. Also includes travel and tourism statistics in its State of the Nation files.

Travel and Tourism
GPO Pathway Services Browse Topic

Travel Spotlight (U.S. Customs and Border Protection)
Includes Customs regulations, travel alerts, restricted goods, pleasure boats and private flyers, airport and border wait times, and the Visa Waiver Program.

Travelers’ Health (Center for Disease Control and Prevention)
Health, immunization, and medical clinic information for specific destinations in the world.