Harmonized Tariff Schedule (HTSUS)

http://www.usitc.gov/tata/hts/bychapter/index.htm

World Airport Codes

http://www.world-airport-codes.com/

Valuable (other) conversions

http://www.hoptechno.com/nightcrew/sante7000/convert.cfm

Currency conversion

http://www.oanda.com/currency/converter/

Recommended Cargo Weights Limits throughout the USA

http://www.ocema.org/cwg.htm