If the latest goofball article by David Brooks on the NYT op-ed page (to add insult to inanity you have to pay to see it) "The Populist Myths on Income Inequality" is driving you nuts, check out Dean Baker's great response. Jared Bernstein also had a similar reaction in his post David Brooks Ruined My Subway Ride.
Dollars & Sense and United for a Fair Economy recently put a book out about the topic, The Wealth Inequality Reader.
D & S regular Chris Tilly wrote a great piece a while back about why inequality is bad in Geese, Golden Eggs, and Traps.