Keep everyone affected by Hurricane Gustav in your prayers. Although it did miss New Orleans, it has still caused a great deal of destruction and many people are separated from their homes. So we are called to lift this up in prayer.
At the same time, as we are called to show the mercy of our Lord to others, we can help in various other ways.
1) Support Christian relief agencies individually such as LCMS World Relief (http://www.lcms.org/page/default.asp?NavID=891). These agencies have the connection of how to help in the most effective way, let them do the dirty work.
2) Organize a group from your church to schedule help to clean up. Organize such efforts through groups like LCMS World Relief/Human Care because once again, they have the connections!
3) Take a door offering at your church this weekend for all affected by the aftermath. Once again, LCMS World Relief/Human Care would be the best place to be directed toward.
Christ have mercy...