Where are the private relief efforts?

It is obvious that government must play a large role in coordinating relief for the hurricane victims in New Orleans, but I've been struck by the absence of private relief organizations from the scene. Where are the churches who could bring in needed food, water, and transportation? Where are the former military guys and private security firms who could help ensure safe passage through the city's streets? Why are the streets not filled with canoes and rafts to bring supplies and to evacuate people still stranded in communities throughout the city? Why aren't there Red Cross and Salvation Army trucks headed down the interstate bringing supplies to those stranded on the interstates?

Government at all levels has already demonstrated its inability and incompetence. Certainly there are many individuals and organizations who have volunteered their time and resources to go into New Orleans and help out. Why are they not there? (Or are they?) I suspect that the answer to these questions is that the government has erected barriers that keep individuals and private relief organizations out of the New Orleans area, in spite of the fact that government has demonstrated its inability to deal with the situation. It's depressing and demoralizing to know that there are people willing to donate their time and resources on site in New Orleans, but for some reason they are not getting there. Absolutely ridiculous.