Several of the national laboratories, such as Argonne National Laboratory in Argonne, IL, offer resident semester exchanges called Science and Engineering Research Semesters (SERS). You receive a weekly stipend, housing, and travel reimbursement, while getting the chance to actually expand the frontiers of knowledge, an activity different from the normal classroom experience. At Argonne, for example, you become a member of a research team, and can become involved in environmental and medical sciences, biology, ceramics, chemistry, physics, engineering, computer science, mathematics, reactor and energy technologies, and materials science.
Students participate in up-to-date research often using one-of-a-kind, sophisticated instruments under the mentorship of a Laboratory staff scientist or engineer. You can take a university-level course for credit. You will also probably supplement the laboratory research experience through attendance at seminars and workshops. This is a great opportunity!