National organizations for undergraduate research, such as WebGURU: Guide to Undergraduate Research and National Conferences on Undergraduate Research list many resources helpful to undergraduates in all stages of their research projects.
Students looking for summer research projects in locations other than Washington University should investigate the following organizations (not an exhaustive list, but a good place to start):
National Aeronautics and Space Administration (NASA)
Undergraduate Student Research Program
National Institutes of Health (NIH)
Clinical Center Summer Internships
Summer Internship Program in Biomedical Research
Undergraduate Scholarship Program
National Eye Institute Summer Intern Program
National Science Foundation (NSF) and Homeland Security
Research Experiences for Undergraduates (REU)
Summer Research in Solid State Chemistry at Oregon State University
Homeland Security summer internship research opportunities at national labs
Howard Hughes Medical Institute (HHMI)
Exceptional Research Opportunities
Additional opportunities
DAAD (German Academic Exchange Service) Journalism Research Program in Germany
National Cancer Institute (NCI) Integrative Cancer Biology Program
National Institute of Standards and Technology (NIST) Summer Undergraduate Research Fellowship
Summer Internship Program at the Institut Pasteur in Paris
Summer Undergraduate Research Scholarship at Nemours/Alfred I. duPont Hospital
University of Michigan Summer Undergraduate Research Opportunitites
University of Washington Environmental Health Research Experience Program
UT Southwestern Summer Undergraduate Research Fellowship Programs