Keychain helps you to manage ssh and GPG keys in a convenient and secure manner. It acts as a frontend to ssh-agent and ssh add, but allows you to easily have one long running ssh-agent process per system, rather than the norm of one ssh-agent per login session.
This dramatically reduces the number of times you need to enter your passphrase. With keychain, you only need to enter a passphrase once every time your local machine is rebooted. Keychain also makes it easy for remote cron jobs to securely "hook in" to a long running ssh-agent process, allowing your scripts to take advantage of key-based logins.
(From http://www.funtoo.org/wiki/Keychain)
Install keychain:
Ubuntu/Debian:
sudo apt-get install keychain
Configure keychain:
Add this to your ~/.bashrc:
keychain ~/.ssh/some.key ~/.ssh/another.key
. ~/.keychain/$HOSTNAME-sh
For every key you need to add the public key in the same directory with the filename $keyname.pub.
For example if you have a keyfile named id_rsa you need the id_rsa.pub in the same directory.
