I have used Orbital Viewer in my introductory and inorganic chemistry courses for the past 4 years. My students and I have found it to be a very useful tool for examining orbital shapes and other aspects of atomic and molecular orbital structure. As with any representation of electron wavefunctions it is important to remind your students that what they are seeing is just that - a representation of a wavefunction drawn as a boundary surface or dot density diagram. When used appropriately the program will greatly enhance student appreciation of a number of aspects of the orbital model. The manual is extensive, but is primarily devoted to the methods used to represent the functions rather than specific applications in chemistry. I have developed a brief tutorial on the basics of Orbital Viewer that can be found at http://www.wellesley.edu/Chemistry/chem341/orbview.html. It is possible to construct animations by placing two or more orbitals at a selected distance and then varying the distance. Examples of such animations, illustrating the formation of diatomic bonding and antibonding molecular orbitals may be found at "http://www.wellesley.edu/Chemistry/chem120/momovies.html">http://www.wellesley.edu/Chemistry/chem120/momovies.html.
I would give this program 5 stars in all three MERLOT categories.