Most of us have to log on to a server while working on a project in our day to day life.
It is annoying to open multiple terminals and enter password for each log in.
So, how about authenticating your local machine permanently to your server login and eliminate entering password for ssh, scp etc.
perform 2 easy steps on your local machine and your goal is achieved:
1. (i) change to directory ~/.ssh;
(ii) ssh-keygen -t rsa
2. ssh-copy-id -i id_rsa @

Now you can log on to the server just by typing "ssh @".(The system will not ask for authentication(i.e password) ).

note : I faced problem if I manually created the .ssh directory in my home directory. This directory is automatically created when one does an ssh or scp.