Mac OS X has pretty good sshkey management, thanks to SSHkeychain.

http://www.sshkeychain.org/

To use it, you have to create a public and private key, using ssh-keygen.

*** We had a little bit of trouble getting this running on the mini mac in the office. In order to get it working we had to edit the ssh config file, then log out, and log back in to reset environment variables.