Business Week on Katrina's impact on economy:
http://www.businessweek.com/bwdaily/dnflash/aug2005/nf20050830_8693_db035.htm
Impact on airlines/travel:
http://money.cnn.com/2005/08/30/news/katrina_air/index.htm?section=money_topstories
Companies who stand to benefit:
http://www.chron.com/cs/CDA/ssistory.mpl/business/3330823