The Omni Group has released
OmniGraffle 4.2,
a general purpose Mac OS X diagramming tool and my
UML editor of choice. 4.2 adds a Document Settings Inspector, can
convert basic shapes to custom polygonal/bezier shapes and vice versa, merges layers, and
improves Visio import and export.
OmniGraffle ranges from $79.95 to $149.95. Upgrades from 3.x and earlier are $29.95. Mac OS X 10.3 or later is required.