The work done with liquid mirrors at Laval University is briefly reviewed. The concept appears sound. It is argued that almost any type of astronomical observations could be carried out with liquid mirror telescopes. As an example, it is suggested how spectroscopy could be implemented on small and large LMTs. Some technical considerations relevant to liquid mirror telescopes are briefly discussed. It is argued that, because the advent of very cheap zenith LMTs should decrease the cost per photon by two orders of magnitude, it could bring about a major increase to the global collecting area of optical telescopes. Telescope time would become far more available than it is now, providing us with more data and allowing greater experimentation. Far more observers would also have access to large telescopes.