It occurs to me that I haven't written about my favorite Catholic economist in a while GK Chesterton. He's got some interesting ideas from the concept of subsidarity- which every Libertarian likes until you try to convince them of the protectionist laws that would be required to break up monopolies and encourage subsidarity.
However, we've got two new problems (which those same neoconservative libertarian "small government" people also like to ignore) that Chesterton didn't have when he was writing: Peak Oil and Global Warming. I suggest that hidden behind a Baltic Dry Index hovering around 0 is a whole lot of oil usage and carbon/sulfur dioxide release, caused merely by having lines of *max container ships constantly running all over the world.
Chesterton's system solves this problem rather neatly- only information is traded between communities, and the principle of subsidarity requires the factory be as close to the end consumer as possible, eliminating the need for shipping.
In addition, this fulfills the second great requirement of solidarity- that the consumers and workers are one, with united interests, against the forces that would centralize economic control, whether that be in government or stock market.
So give ol' GK a read sometime- and open your mind up to a third possibility, a Civilization of Love rather than a Civilization of the State or a Civilization of the Market.