Lattice mapping system is based on the idea that all geometric objects define three dimensional parameter space (also called uvw space). For example, the 'u' coordinate for the nurbs curve runs along the curve whereas the two other dimensions are perpendicular to the curve.
The parameter space for the nurbs mesh is such that the first two dimensions corresponds to the parameter space of the nurbs mesh whereas the third dimension corresponds to the surface normal of the mesh.
Any object can be mapped into this parameter space, in which case the coordinates of the mapped object are defined in the parameter space of the lattice object rather than in the world space. When the lattice object is then modified, the mapped geometry will get modified accordingly.
Lattice mapped objects can be animated. For example, a sphere moving in 'x' direction in the parameter space of the curve means that the sphere moves along the curve.
The Lattice Mapping tool group in the Tools tab of the Available GUI Objects window (opened by selecting the Environments/Customization/Available Object Window... menu) contains the lattice mapping tools.
These tools can be drag&dropped to a tool bar.