THE MONEY: Mapleton Investments has money spread across real estate, art, stocks and bonds. Falcon Waterfree Technologies saw sales up especially internationally.

BUZZ: Nathanson and wife, Jane, more involved with philanthropy, arts and politics than business. Floor at Broad Contemporary Art Museum at Los Angeles County Museum of Art named for couple, who donated $10 million to museum in 2008. Avid art collectors for almost 50 years, recently added sculpture by American pop artist Roy Lichtenstein to collection, which is said to exceed 550 pieces. Marc Nathanson founded Falcon Communications in 1975 and sold it to Microsoft co-founder Paul Allen for $3.7 billion in 1999. Made substantial investment in 2000 in West L.A. waterless urinal maker Falcon Waterfree Technologies, where he serves on board with son David. Occupied with six grandchildren, ranging in age from 1 to 13. Enjoys fly-fishing and spending summers at family home in Aspen, Colo.

NET WORTH:

$1.33 billion s13%

LAST YEAR: $1.18 billion

AGE: 69

RESIDENCE: Holmby Hills

SOURCE OF WEALTH: Communications, real estate, art