From time to time these interesting crayfish threads pop back up. If Mr. Cody or snrub are maintaining an archive then I would add this slide show link. I know this is a wealth of knowledge on identifying crayfish that is beyond most of us, but I bet Mr. Cody will feel very comfortable reading through this.
I found the pictures of the molt and the more obvious differences in the photos in the adult male and female crayfish to be very helpful. I now know what to look for when the crayfish are 'in berry' as well.
take a look through this interesting presentation.
Crayfish ID Resource - Great Pictures!! This webpage also has many crayfish with pictures and more information.
Picture ID of crayfish common in southern US states