Joy Shivar, an antiques dealer in Huntersville, N.

WSJ: Using Wikis and Other Forms of Group Research, Family Historians Are Making Surprising Connections

John Casino, 40, is a dealer in German military artifacts in Nutley, N.

FORBES: Collecting Evil

Grant McKinnon, a poster dealer in San Francisco, explains that in the rock'n'roll field, many of the original artists, printers and negatives are still around, so primary-source knowledge is fairly easy to come by.

ECONOMIST: Print graphics

When Eric Will, an upstate New York dealer in industrial equipment, bought a defunct Miller brewery near Syracuse, N.

FORBES: Magazine Article