Since MC was asking about picture preservation, I asked my mom for some advice - and the first thing she said to do with pictures that have been in a flood is to FREEZE THEM.
Apparantly this will keep mildew from spreading, and then it is possible to have the water extracted dryly. (Sounds like an oxy moron, but it works!)
She has a photo lab here in seattle that does custom work, including photo restoration, copy negs and more. If anyone wants more info, email me and I'll give you there #.
They dont' have a website - even though they SHOULD - but that's another story.
Jessica