I can't recall now where I stumbled on this, but if you have time and a computer, then you've got to go here and do this:
Katrina Wiki People Finder Volunteer
It's a matter of taking raw data that people have posted to Craig's List and many other places, and entering the information into forms to be put into one giant database.
Do a little, do a lot, but do it. There are plenty of tips to guide you through any confusion.