Description:

keychain helps you to manage RSA and DSA keys in a convenient and secure
manner. It acts as a frontend to SSH-agent, 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 RSA and DSA
keys.

Run keychain once manually per user, after which keychain will run (quietly)
every time you log in (from a profile script).

Hint: If you get tired of keychain, delete ~/.keychain