An apparatus comprising: a first housing having an upper surface , a bottom surface , and at least a first cam ; a second housing having an upper surface and having at least a second cam ; a link configured and disposed to slidingly engage the first cam and the second cam; wherein the first cam, the second cam, and the link are configured such that the first housing is movable with respect to the second housing between a first position and a second position, wherein: each of the bottom surface of the first housing and the upper surface of the second housing comprises a first planar portion, a second planar portion and a non-planar portion for connecting said first and second planar portions, the first position comprises a stacked configuration with the first housing disposed atop the second housing and the bottom surface of the first housing adjacent to the upper surface of the second housing ; and the second position comprises a deployed configuration with the upper surface of the first housing disposed at least substantially coplanar to the first planar portion of the upper surface of the second housing , wherein the bottom surface of the first housing and the upper surface of the second housing conform to one another and interlock with one another in the stacked configuration and in the deployed configuration. a first housing having an upper surface , a bottom surface , and at least a first cam ; a second housing having an upper surface and having at least a second cam ; a link configured and disposed to slidingly engage the first cam and the second cam; wherein the first cam, the second cam, and the link are configured such that the first housing is movable with respect to the second housing between a first position and a second position, wherein: each of the bottom surface of the first housing and the upper surface of the second housing comprises a first planar portion, a second planar portion and a non-planar portion for connecting said first and second planar portions, the first position comprises a stacked configuration with the first housing disposed atop the second housing and the bottom surface of the first housing adjacent to the upper surface of the second housing ; and the second position comprises a deployed configuration with the upper surface of the first housing disposed at least substantially coplanar to the first planar portion of the upper surface of the second housing , wherein the bottom surface of the first housing and the upper surface of the second housing conform to one another and interlock with one another in the stacked configuration and in the deployed configuration. each of the bottom surface of the first housing and the upper surface of the second housing comprises a first planar portion, a second planar portion and a non-planar portion for connecting said first and second planar portions, the first position comprises a stacked configuration with the first housing disposed atop the second housing and the bottom surface of the first housing adjacent to the upper surface of the second housing ; and the second position comprises a deployed configuration with the upper surface of the first housing disposed at least substantially coplanar to the first planar portion of the upper surface of the second housing , wherein the bottom surface of the first housing and the upper surface of the second housing conform to one another and interlock with one another in the stacked configuration and in the deployed configuration. <EOS>