- Make a backup copy of your ~/Library/Application Support/Camino folder.
- Download Dropbox, then activate a Dropbox account if you have not done so already.
- On your first machine, move (not copy) your ~/Library/Application Support/Camino foder to your Dropbox folder.
- Symlink your user's ~/Dropbox/Camino folder to ~/Library/Application Support/Camino with this Terminal command:
$ ln -s /Users/Dropbox/Camino /Users/Library/Application\ Support/Camino - Repeat the same move/symlink process on your second (and third, etc.) Mac.
[robg adds: I haven't tested this one. The basic process could be used to sync settings in many types of apps, obviously.]

