  Motivated by the co-existing charge and spin order found in strongly
correlated ladder systems, we study an effective pseudospin model on a coupled
two-leg ladder. A bosonisation analysis yields a rich phase diagram showing
Wigner/Peierls charge order and Neel/dimer spin order. In a broad parameter
regime, the orbital antiferromagnetic phase is found to be stable. An
intermediate gapless phase of finite width is found to lie in between two
charge-ordered gapped phases. Our work is potentially relevant for a unified
description of a class of strongly correlated, quarter-filled ladder systems.
