Say what you will about his causes, author, political commentator and television host Tavis Smiley has developed a different kind of activism.

His mostly black, middle-class audiences don't carry picket signs. They don't hold sit-ins or go on freedom marches. And nobody has to take time off from their desk jobs because they got themselves arrested during a street protest.

"Advocacy has gotten so much easier today," says Smiley, host of the current affairs talk show "BET Tonight With Tavis Smiley," whose social commentaries can be heard on the nationally syndicated radio program "The Tom Joyner Morning Show."

"We have more disposable income. We don't have to do any fish fries or chicken fries. Of all the things we've done on 'The Tom Joyner Morning Show,' we have never called for a rally or a march anywhere. We are using faxes and phone calls. We are using modern technology."

Smiley's highest-profile campaigns employ these modern tactics against corporate adversaries. They basically go like this: Smiley targets companies that he feels insult African American consumers. Then he and many of his 7 million listeners flood them with letters, bring business to a standstill by shutting down their telephone lines with faxes and calls and use negative publicity to affect the value of their stocks.

Smiley recounts several recent successes: temporarily reviving the Fox television show "Living Single"; lobbying for the Congressional Gold Medal for Rosa Parks; thwarting plans by the Christie's auction house to sell slave artifacts; blasting the Katz Media Group for a racist memo; and, most recently, pressuring executives at CompUSA to increase advertising to minorities.

Smiley's tactics have not escaped criticism, and a few serious blunders have harmed his credibility. During the CompUSA imbroglio, for example, Smiley and Joyner had to apologize on the air for railing against a racist fax, purportedly written by a company executive, that they later learned was a hoax. They also alleged that the CompUSA board was all white, another error they had to retract.

In Smiley's new book, "Doing What's Right: How to Fight for What You Believe--and Make a Difference," which he will sign tomorrow at Karibu Books in Hyattsville, he acknowledges that the bogus fax rattled him, and that he considered abandoning the campaign altogether. However, he decided the cause was too important to give up.

"It would have been a terrible precedent," he writes. "I had taken my listeners halfway down this path, and they were looking to me for leadership."

In the end, Smiley declared victory after settling with CompUSA. In the book, he sets out to create a blueprint for people interested in having a similar impact on their own communities.

"We have textbooks, manuals and guides for everything in America, except how to make a difference when you find something about which you are passionate," Smiley says, explaining why he wrote the book.

The work offers straightforward tips on organizing a movement, from dealing with the media to building an Internet site, from designing a phone tree to making contacts. He doesn't specify which causes people should advocate; in fact, the book includes a three-page work sheet that helps readers identify issues they care about and what they can do about them.

Smiley, 35, says members of his generation are not as responsive to traditional black civil rights groups, to which they nonetheless owe much. Instead, he says, more young people are looking to black professional groups to help them get ahead.

"It is more economic now. We are all trying to climb that corporate ladder," he says, noting that there are more young African Americans in positions of authority and leadership than ever, including Democratic Reps. Harold E. Ford Jr. (Tennessee) and Jesse L. Jackson Jr. (Illinois).

"We are the realization of King's dream," Smiley says of the Rev. Martin Luther King Jr. "We are the first generation not born of struggle. I think that makes a book about advocacy more important than ever."

Though Smiley advocates social initiatives, many of his crusades have symbolic rather than practical outcomes. Smiley acknowledges that he is better known for his corporate muckraking, because those campaigns tend to draw more media attention than public policy initiatives such as making sure African Americans are counted in the 2000 Census.

"I'm not going to tell you that [the battle for more positive black media images] is the most important fight," Smiley says. "It is incumbent that all of us fight on different levels. There are enough of us to fight different fights simultaneously."

In "Doing What's Right," Smiley describes how people can further a multiplicity of causes. But, of course, black America's most urgent problems--hunger, drugs, homelessness and deteriorating public schools, for example--couldn't be solved by a zillion faxes.

"There are only so many issues that I can advocate," Smiley says. "I'm putting my book out there and challenging folks to respond."

Tavis Smiley reads from and signs "Doing the Right Thing" tomorrow from 6 to 8 p.m. at Karibu Books, 3500 East West Hwy., Hyattsville. Admission is free. For more information, call 301-559-1140.

CAPTION: Tavis Smiley delivers his weekly commentary on the nationally syndicated radio broadcast "The Tom Joyner Morning Show" from the ABC Radio studios.