  We consider Fell bundles over discrete groups, and the C*-algebra which is
universal for representations of the bundle. We define deformations of Fell
bundles, which are new Fell bundles with the same underlying Banach bundle but
with the multiplication deformed by a two-cocycle on the group. Every graph
algebra can be viewed as the C*-algebra of a Fell bundle, and there are are
many cocycles of interest with which to deform them. We thus obtain many of the
twisted graph algebras of Kumjian, Pask and Sims. We demonstate the utility of
our approach to these twisted graph algebras by proving that the deformations
associated to different cocycles can be assembled as the fibres of a C*-bundle.
