The U.S. Department of Homeland Security has implemented the US-VISIT program. The program will use biometrics to track international visitors who hold non-immigrant visas when they enter and leave the United States. This means that they will be collecting traveler’s fingerprints and photographs as they enter the US. There is no fee associated with the program.

These procedures are mandated by U.S. laws and are intended to reduce fraud, identity theft, and the risk that terrorists and criminals will enter the United States undetected.

More information is available at the DHS web site below.
http://www.dhs.gov/dhspublic/display?theme=43&content=736

Canadian citizens are currently exempt from the US-VISIT requirements since they are not required to have a visa. Be sure to check the government web sites above for any changes. The government websites change daily. Be sure to check them often.