IT WAS 1987 and I was pursuing a story born in my childhood when I met a genteel, diminutive postal official who offered a few words of advice that changed my career. He was the late Belmont Faries, a retired Washington Star news editor.

As chairman of the Citizens's Stamp Advisory Committee, Faries had been one of the most influential people in the design of U.S. postage stamps, and I was attempting to pierce the veil of secrecy around how the Postal Service selects its stamps. It was a subject that had remained a mystery since I had collected my first stamps as an elementary school student.

Faries defended the selection, saying that postmasters general control the selection process. Why, one postmaster general, William F. Bolger, "couldn't go to a cocktail party without giving out a stamp or two," Faries recalled with a chuckle.

In response to one of my questions, Faries said he didn't think much of the syndicated stamp column The Post was running. "A copy aide could write a better one," he said.

I hadn't collected a stamp in years, but that was all the challenge I needed. Within a few days, I had convinced the editor of Weekend that I could write a better Stamp & Coin column, one that would focus on how Washington selects the nation's stamps and coins.

It was the beginning of a wonderful 12-year odyssey with some of the most delightful and kind people who read this newspaper. My aim never has been to write a column just for collectors, but a column for anyone who uses stamps and coins. If what I have written has helped you understand why one stamp or coin was issued, then I believe I succeeded.

Since I began, U.S. stamps and coins have undergone dramatic changes. Not only did the subjects of U.S. stamps change, but so have has their format.

Blame it all on Elvis. The controversial 1993 release of the 29-cent commemorative honoring Elvis Presley in 1993 literally shook up the public's perception of who should be on a stamp. After it was released on a rainy night at Graceland, the public demanded -- and got -- more contemporary stamp subjects.

The often obscure political figures of Faries's era -- the "dead heads" as some postal officials called them -- were out. Relatively recent figures from American pop culture, among them Marilyn Monroe, Hank Williams and the Beatles, were in.

Former postmaster general Anthony M. Frank changed the face of American stamps with his decision to place Presley on a stamp. Then, Marvin T. Runyon, Frank's successor, changed the format of a stamp. A former automobile executive, Runyon decreed that self-adhesive stamps be sold for the same price as lick-and-stick stamps, a decision that doomed the old format.

Before he left office two years ago, Runyon also ordered the return of social causes to postage stamps and directed the development of computer-printed stamps.

Still, in stamps as in most news, it's mistakes that make headlines. Every stamp collector lives to find a misprint and, despite all of its efforts to avoid mistakes, the Postal Service provided a few spectacular ones in the past 12 years.

There was the cloak-and-dagger tale of the CIA and its band of mailroom workers. They discovered the last major stamp error, a misprinted $1 candlestick stamp. After the workers took the misprint out of the agency's mailroom and sold the remaining stamp in the sheet to a stamp dealer for big profits, word of their dealing leaked out. It ultimately got them in serious trouble with the agency.

And there was the discovery that an engraver had secretly slipped a Star of David into the design of another $1 stamp, forcing a reexamination of the dies of all recent U.S. stamps. The checking failed to find another secret design, but, not to worry, the Postal Service was able to produce another major error. In 1994, the agency had to destroy millions of cowboy stamps after it belatedly discovered it had printed the wrong image of Wild West rodeo rider Bill Pickett on its "Legends of the West" stamps. A handful of the misprints had been sold before the error was detected, creating a furor that prompted postal officials to stage a lottery to offer collectors a chance to buy 150,000 sheets containing the wrong Pickett stamp.

No errors of that magnitude have popped out of the U.S. Mint in the past 12 years, but, pardon the pun, coin production may be on the verge of major change. Congress's decision to honor the 50 states with designs on the quarter may presage a change in all the nation's coinage, a revision collectors have been arguing for for years is long overdue.

And if the public accepts the new gold-colored $1 coin bearing the image of Sacagawea, the Native American guide, the change could have a profound impact in Washington. Its acceptance would seriously undercut demand for $1 bills, the primary product of the 14th Street plant of the Bureau of Engraving and Printing.

Given all these changes, it's difficult to predict what's ahead for either the nation's stamps or coins. One thing is certain. I'm grateful to the many of you who have helped me chronicle the past changes. You've been great sources -- and great readers.

This is Bill McAllister's final Stamps and Coins column for Weekend. He now works for The Denver Post.