  LXeGRIT is the first prototype of a novel concept of Compton telescope, based
on the complete 3-dimensional reconstruction of the sequence of interactions of
individual gamma rays in one position sensitive detector. This balloon-borne
telescope consists of an unshielded time projection chamber with an active
volume of 400 cm$^2 \times 7$ cm filled with high purity liquid xenon. Four VUV
PMTs detect the fast xenon scintillation light signal, providing the event
trigger. 124 wires and 4 anodes detect the ionization signals, providing the
event spatial coordinates and total energy. In the period 1999 -- 2001, LXeGRIT
has been extensively tested both in the laboratory and at balloon altitude, and
its response in the MeV region has been thoroughly characterized. Here we
summarize some of the results on pre-flight calibration, event reconstruction
techniques, and performance during a 27 hour balloon flight on October 4 -- 5.
We further present briefly the on-going efforts directed to improve the
performance of this prototype towards the requirements for a base module of a
next-generation Compton telescope.
