Abstract: A ball and socket joint for connecting one end of a rail member to a base member includes a ball mounted on the end of the rail member. A socket and a radial slot in the base member permit pivoting of the rail section relative to the base between a first position and a second position. The socket also permits rotation of the ball in the socket to permit rotation of the rail member about its longitudinal axis relative to the base member between a locked orientation and a unlocked orientation. When the rail section is in the locked orientation it cannot pivot relative to the base member and when the rail section is in the unlocked position it is free to pivot relative to the base member.

Abstract: An interactive book or device having a mechanism for generating a plurality of sensory outputs in manner that maximizes the interaction between the user and the book or device. The interactive book includes function initiators for initiating a unique sensory output that corresponds to a visual indicia on a page of the book. A function level selector is coupled to the function initiators that selectively changes a function level and thereby selectively changes the sensory output corresponding to each function initiator. Consequently, the number of sensory outputs is increased and thereby enables greater interaction between the user and the book. It also encourages the user to creatively combine the sensory outputs to obtain a cognizable aggregate output.