Collect all .ssh folders

Set up a folder call ~/Documents/keys on the collector system

Using tmux-cssh, log in to all source systems.

On all source systems, enter:

tar -cvzf $HOSTNAME.tar.gz ~/.ssh/* && scp $HOSTNAME.tar.gz jeff@calypso:/home/jeff/Documents/keys

You should now have all systems (assuming that they could scp to the collector) listed in the keys folder, with the source hostname in the filename.