Key Manager is designed to allow distribution and management of SSH keys in a way that scales beyond manually copying public keys to remote hosts. This approaches Single-Sign-On functionality, if limited to ssh access from a single host.
A graphical user, group, and computer account manager for LDAP servers. Doesn't try to be the end-all LDAP tool, focuses on making user management quick and easy. (For linux/gnome, windows, MacOS coming RSN)