Finally, a worthy successor to the Pet Rock: celebrity dirt. In the past two years, Barry Gibson of Lansing, Mich., has sold 20,000 vials of the stuff, dug from the yards of such luminaries as Michael Jackson, Madonna, and Johnny Carson's ex-wife Joanna. (The latter was actually a mistake: Gibson thought the talk-show host was still living there. "I sent him a vial with a note that said, 'Here's some of what you lost in your divorce.' ")

Gibson, who also owns a janitorial service and an ice-cream shop, does all his own digging. He has spent about $5,000 on dirt-gathering trips around the country, carrying $500 in bail bond, just in case he gets nabbed for trespassing. To date, his closest call came when Katharine Hepburn almost caught him on her grounds.

The two-inch vials retail for $1.89, complete with a certificate of authenticity and suggested uses -- a celebrity mud-slinging party, for instance. Still, major department stores won't carry the product because, Gibson says, they fear lawsuits. Meanwhile, his company, Barex Inc., has yet to turn a profit. But he refuses to throw in the trowel. "The Pet Rock sat on the shelf for a couple of years, too," he says.

-- Joshua Hyatt