Suppose you have two machines, the local one (your laptop) and the remote one (the honking big server located in Minneapolis that hosts gitdown.com) To ssh (or CVS) from the laptop to the server without needing a password, perform these steps:
% ssh-keygen -t rsa
(don't use a passphrase. Just hit return twice)
% scp ~/.ssh/id_rsa.pub gitdown.com:
- On the remote machine (gitdown)
% cat ~/id_rsa.pub >> ~/.ssh/authorized_keys