  We study the metal-insulator transition and magnetic ordering in the Hubbard
model using the particle-hole mapping. The analysis simplifies near the
ferromagnetic limit. We find that the two dimensional(2D) Hubbard model has a
charge excitation gap at half-filling for any finite U in this region on both
the bipartite square lattice and the nonbipartite triangular lattice. In some
cases, the system goes through a first-order phase transition to become a
paramagnetic metal as $S_{z}$ is lowered. We also discuss the extension to the
doped case. We find that in the large U limit, a single doped hole has a
bandwidth of order of J rather than t at $S_{z}=0$.
