The REU programs also extend to specialized fields in physics and other areas related to physics.  A partial list of these opportunities is included below.

DOE Research Labs

Topic: All sciences
URL: http://energy.gov/offices

Argonne National Lab

Topic: All sciences
URL: http://www.anl.gov/

NSF Opportunities

Topic: All sciences
URL: http://www.nsf.gov/funding/

Office of Naval Research

Topic: All sciences
URL: www.awu.org/onr

Univ. of Wisconsin Madison

Topic: Physics & Engineering
URL: http://www.engr.wisc.edu/ep.html

NIST/SURF program

Topic: Physics/Mat Sci  URL: www.physics.nist.gov or www.msel.nist.gov

Univ. of Central Florida

Topic: Optics
URL: http://www.creol.ucf.edu/

Mt. Wilson Obs. (U-WI)

Topic: Astronomy
URL: http://www.mtwilson.edu/

Georgia State University

Topic: Astronomy
URL: http://www.chara.gsu.edu/

Cornell

Topic: Material Science
URL: http://www.mse.cornell.edu/

Johns Hopkins

Topic: Material Science
URL: www.pha.jhu.edu/groups/mrsec/reu.html

Washington Univ., St. L.

Topic: Civil Engineering
URL: http://wustl.edu/

The following are points of contact for more permanent positions after graduation:

AFIT (Work study)

Topic: Aerospace Sci
URL: http://www.afit.edu/ADMISSIONS/

USDA Colorado State Univ.

Topic: Atmospheric science
URL: http://www.colostate.edu/

Peace Corps

Topic: All sciences/educ
URL: www.peacecorps.gov