You can donate funds from your auctions to hurricane relief aid by using the eBay Giving Works program.  There's also more info on eBay about where you can make a donation.  Also included are links the USPS and UPS have provided about delivery problems to affected areas. Here's the announcement:
 
We at eBay are saddened by the continued damage to the Southeast United States as a result of Hurricane Katrina. As rescue efforts continue, we want to make it as easy as possible for the eBay Community to help.

We've set up several ways for you to donate funds to the relief efforts. You can buy or list items to support a relief organization with eBay Giving Works [http://givingworks.ebay.com/?ssPageName=CMDV:AB]. A section of the eBay home page has been dedicated to relief efforts and information, and contains a link to our donation page [http://www.paypal.com/cgi-bin/webscr?cmd=xpt/cps/general/PayPalKatrinaReliefEffort-outside] on PayPal so that you can make a direct contribution to the United Way. You can also visit the Natural Disaster & Relief Information discussion board.
http://forums.ebay.com/db1/forum.jspa?forumID=1000000000&ssPageName=CMDV:AB

In addition, the eBay Foundation is making a $250,000 donation to the American Red Cross on behalf of the eBay Community.

Please also keep in mind that many people have been displaced by this disaster, and others may not be able to access their computers or ship or receive items. We encourage you to be patient and to keep trying to communicate with any transaction partners in the affected areas. Additionally, both the U.S. Postal Service and United Parcel Service have posted information about their services to the affected areas on their respective websites. You can find the USPS information here [http://www.usps.com/communications/news/serviceupdates.htm] and the UPS information here.
http://www.ups.com/content/us/en/about/news/service_updates/Katrina.html

Sincerely,

Rachel Makool
Director, Community Development