http://olivier.sessink.nl/jailkit/

Jailkit is a set of utilities to limit user accounts to specific files using chroot() and or specific commands. Setting up a chroot shell, a shell limited to some specific command, or a daemon inside a chroot jail is a lot easier and can be automated using these utilities.

Jailkit is used in network security appliances from several well known manufacturers, internet servers from several large enterprise organisations, servers from internet service providers, as well as many smaller companies and private users that need to secure cvs, sftp, shell or daemon processes.