Keychain

The keychain script makes handling RSA and DSA keys both convenient and secure. It acts as a front-end to ssh-agent, allowing you to easily have one long-running ssh-agent process per system, rather than per login session. This dramatically reduces the number of times you need to enter your passphrase from once per new login session to once every time your local machine is rebooted.

Link: http://www.gentoo.org/proj/en/keychain/