volman is a FreeBSD specific volume manager.  It acts
as a translator of devd(8) events, probing storage
devices for their file system information, and serving
this over a FIFO based API to which clients can
subscribe.  In addition to notifying clients of new
or lost volumes, it will mount and unmount such
volumes at the command of subscribing clients.

It runs as root and allows any local clients the
ability to mount and unmount volumes which are
detected, regardless of any user privileges.  This
is intended for single user X11 systems needing
an easy way of accessing USB flash disks on the fly.

WWW: http://forums.freebsd.org/showthread.php?t=27233