(March 28) -- Letter writers soon will be able to put pen to paper, slip it into an envelope — and seal it with a Sith.

A set of 15 commemorative stamps featuring characters from Star Wars is set to be unveiled today by the U.S. Postal Service in what may be the most popular philatelic event since Skinny Elvis beat out Fat Elvis in the early 1990s.

The stamps will be revealed this morning at the historic Chinese Theatre in Hollywood, one of a handful of theaters that showed the original Star Wars when it opened May 25, 1977.

To commemorate that 30th anniversary, the stamps will go on sale May 25, USPS marketing director Anita Bizzotto says, joking, "Two big Forces are uniting."

The Citizen Stamp Advisory Committee's decision to recognize Jedi, droids and evil Sith lord Darth Vader is part of the Postal Service's tradition of paying tribute to pop culture.

"We've done Disney characters, Jim Henson  and the Muppets, Hershey's kisses and comic book characters," Bizzotto says. "Star Wars is part of our culture. It speaks to all generations."

Star Wars creator George Lucas  was not involved in the process, but "he blessed the idea of it, and when the artwork was finished, he loved it," says Howard Roffman, president of Lucas Licensi