  We introduce blow-up and blow-down operations for generalized complex
4-manifolds. Combining these with a surgery analogous to the logarithmic
transform, we then construct generalized complex structures on nCP2 # m
\bar{CP2} for n odd, a family of 4-manifolds which admit neither complex nor
symplectic structures unless n=1. We also extend the notion of a symplectic
elliptic Lefschetz fibration, so that it expresses a generalized complex
4-manifold as a fibration over a two-dimensional manifold with boundary.
