  Large liquid scintillation detectors have been generally dedicated to low
energy neutrino measurements, in the MeV energy region (as for example, KamLAND
and Borexino). Herein we describe the potential employment of large detectors
(>1 kiloton) for studies of higher energy neutrinos interactions, from the
cosmic rays and as a long baseline neutrino detector. Generally when people
have considered large new instruments such as Hanohano and LENA, they have
abandoned the possibility of doing useful measurements with higher energy
neutrino interactions since these produce enough light to illuminate every
photomultiplier tube, and the scintillation light is isotropic. Here we take
into account Fermat's principle, which tells us that indeed the first light to
reach the PMTs will be on or near the lightcone, the "Fermat surface", and that
directional track information is available. Moreover we have realized that
particle type distinction is possible (quasi-elastic muons from electrons). In
fact the resolution from a detector of comparable size to SuperKamiokande, may
be better in both angle, energy and possibly particle type. This realization
opens the doors to a number of applications. Moreover, this capability can be
demonstrated with the use of (future) KamLAND detected events in the new long
baseline neutrino beam from the Jaeri accelerator in Japan, due to start
operations this year. Some of the most attractive possibilities for the future
may be in using Hanohano as a movable long baseline detector in this same beam,
the employment of LENA in Europe in future long baseline neutrino beams from
CERN, and in the DUSEL underground laboratory at Homestake.
