Keep up with what's happening in the Physics Department.
Opportunities listed at Oxy's URC: http://www.oxy.edu/undergraduate-research-center
Summer Options at Caltech & JPL: SURF http://www.surf.caltech.edu
A search engine specifically designed to help undergraduates find summer sresearch programs: http://www.thenucleus.org/research/
REU (Research Experience for Undergraduates) programs funded by the NSF: http://www.nsf.gov/crssprgm/reu/reu_search.cfm (search for an REU site)