cleolinda has been compiling news stories and links about what's going on in New Orleans. There are links to how to find a reliable charity to donate to, firsthand reports on what's happening and ways you can help.
Also, a close friend of mine is running in a marathon on October 2nd for a cure for breast cancer. Information is
here on her journal.
It's anarchy in New Orleans right now. I don't know anyone there personally, but I'm scared for everyone there just the same. I've heard from many sources that if you want to help, sending money rather than supplies is better, because by the time the supplies are shipped, the money spent on shipping could have been used more economically to buy supplies in bulk. Donating money is best, but you should make sure it's a reliable charity. (I've actually heard some negative things about the Red Cross, so check around a little more before just donating.)
I'm trying to think if there's anything I can do to help raise money, but I don't have nearly enough online presence to make a stir. Right now, I hope Big Name Fans and other LJ personalities take some action to raise money. We need a movement on LJ and through fandom like we had for the 2004 election and the tsunamis and the hurricanes.
For now, I'm going to play around on Photoshop and see if I have any marketable skills that can be used to raise money.
ETA:
call_to_action should be interesting.