Person to know: Warren Cohn.

I love punctuality," says Warren Cohn when I call him at exactly 10:30 A.M. for a phone inter view. As vice president of Mellon Financial Corp.'s private wealth management group, Cohn needs to keep punctual, considering his client base of high-net-worth individuals and his responsibility for billion-dollar investments.

Born in Atlanta and raised in South Florida, Cohn, 35, has vaulted himself into one of the most dynamic jobs in the financial industry. Based in Los Angeles, he is investment management house Mellon's representative to the city's megawealthy, including some of the most notable film, TV, and sports stars in the world. (No, Cohn wouldn't name names.)

Once an investment banker at PaineWebber, Cohn made a personal discovery after finishing graduate school in Florida. "I realized the world of private wealth was a lot more enjoyable than institutional wealth," he says.

Mellon is neither a retail bank nor a brokerage firm; it's a company that manages assets, including the often misunderstood hedge funds. Simply put, a hedge fund, Cohn explains, "is a contrarian investment to hedge against loss," comprising a pool of money invested on behalf of clients. Investments can be made in a variety of assets, including stocks, bonds, horses, wine, and even film production.

Since Mellon does not advertise or coldcall potential investors, Cohn relies on word-of-mouth referrals and his own reputation. That means his schedule is very flexible. "If somebody calls me tomorrow and says, 'I've got $20 million,' I'm going to get on the plane and go meet with them," he says. He'll then put together a team of Mellon staffers to handle such clients once they come on beard. As he puts it, "I play the quarterback."

Being openly gay in the financial industry, Cohn says, hasn't been a problem, particularly at Mellon, which scored a perfect 100 on the Human Rights Campaign's 2006 Corporate Equality Index. A member of the firm's LGBT employee group, he says his "three passions are gay causes, youth causes, and StandUp for Kids," a national advocacy group for runaway youths. He also works with gay rights groups Lambda Legal and Equality California and serves on the board of the Trevor Project, an organization working to curb suicide among queer and questioning youths.

But his sexuality does not define him, Cohn says--even if many people joke that he's "the straightest gay guy they know."