http://www.vanderbilt.edu/katrina/index.html
"Area undergraduates interested in coursework at Vanderbilt should apply as a Visiting Student - under the category of Transient Student - through the Division of Unclassified Studies (DUS). No application fee is required due to these special circumstances, and applicants will be notified of their admission status to DUS within 24 hours. Applicants should be prepared to participate in a rigorous educational environment and must be residents of Middle Tennessee or have immediate family in the area. Vanderbilt can best serve interested Visiting Students if they submit their application in person so that a member of the Registrar's office can discuss individual curriculum needs and course availability.
...Because the fall semester began at Vanderbilt on August 24th, September 7th is the final day on which students can begin attending classes at the university as a Visiting Student. "