  A new approach known as flat histogram method is used to study the +/-J Ising
spin glass in two dimensions. Temperature dependence of the energy, the
entropy, and other physical quantities can be easily calculated and we give the
results for the zero-temperature limit. For the ground-state energy and entropy
of an infinite system size, we estimate e0 = -1.4007 +/- 0.0085 and s0 = 0.0709
+/- 0.006, respectively. Both of them agree well with previous calculations.
The time to find the ground-states as well as the tunneling times of the
algorithm are also reported and compared with other methods.
