Personalized ring tones -- 30-second sound bites that loop until a cell-phone call is answered or banished to voice mail -- are here to stay. As a means of personal expression, they've become second only to wardrobe.

Steven Franklin, for instance, answers his phone to Petula Clark's "Downtown."

"I started living in downtown Las Vegas about seven years ago and now I sell real estate almost exclusively downtown," says the Realtor, who calls himself Downtown Steve.

Prerecorded ring tones are easy to obtain. Users can choose from thousands posted on cell-provider or third-party Web sites, which are then instantly beamed to their phones.

"It's an audio version of a concert T-shirt," says Antony Bruno, digital editor for Billboard magazine. "You buy one so you can walk around with a badge saying, 'Hey, I'm a fan of this artist.' This is the badge of who I am and who I like.

"Or you just think (the ring tone) is funny."

As with all freedoms, however, ring-tone choice comes with a price (besides the per-download charge of $1.99 to $2.99). Many bystanders are exposed, at times, to ring tones that offend them.

If the man at the checkout stand isn't quick enough to answer his phone, for instance, flatulence sound effects commence and Larry the Cable Guy complains, "I gotta poop!"

"Why is it that the people who have the loudest, most obnoxious ring tones are the ones that just can't ever get to their damn phone?" asks KLUC-FM, 98.5 radio personality Chet Buchanan. "I could frisk them and find their phones sooner than they do."

The first ring tones, launched a decade ago, were monophonic, meaning that only one note played at a time. The best known -- "Nokia Tune," a 13-note version of "Gran Vals," a 19th century composition by Spanish guitarist Francisco Tarrega -- is still ubiquitous today.

In 2002, the Nokia 3510 became the first phone capable of playing polyphonic tones (multiple notes at once). By 2003, both Nokias and Motorolas were playing digital audio recordings of songs and celebrity voices. And by 2005, Larry the Cable Guy was farting in our ears at Vons.

Other offensive ring tones reported by R-J readers include blood-curdling screams, any sound associated with the computer-animated character Crazy Frog, and "The Macarena."

" 'The Macarena' is tangible evidence of evil," says Tupperware manager Amy Reichenbach. "That should never be played in public."

In addition, although cell providers won't sell ring tones with obscene language, it's now possible for anyone to make a ring tone of any sound using software titles such as MAGIX Ringtone Maker, Xingtone Ringtone Creator and Oxygen Phone Manager, which are growing in popularity.

Even normally tolerable ring tones can become intolerable in inappropriate places. Chris O'Connell, heating and air-conditioning engineer at Luxor, says he attended a funeral for a friend when his "Born to Be Wild" by Steppenwolf ring tone went off.

"It was during the eulogy," O'Connell reports, "while the priest was telling about my friend's virtuous ways."

Teller of Penn & ... -- who uses the theme song for the late Jay Marshall's ventriloquist act as his ring tone -- says he hates "any ring" that goes off during his show.

"There's nothing like setting a creepy, Gothic mood to creep up on the shadow of a rose and murder it," he says, "and suddenly you hear, 'VRING! VRING!' "

Ring tones are not going anywhere, however. Last year, they generated $6.6 billion in worldwide revenue (7 percent of all record-label incomes), forcing Billboard to launch a chart tracking the most popular. (Last week's was an uncredited recording of what is alleged to be the New York Stock Exchange starting bell.)

"They've become a considerable force," Bruno says.

Cell-phone addicts also find ring tones useful for distinguishing between callers, each of whom can be assigned a different tone.

"That way, I know who's calling before I check Caller ID," says Reichenbach, who admits moving quicker for "You Give Me Something" by James Morrison (her husband's ring tone) than the "Halloween" movie theme (anyone she doesn't want to deal with).

"But you have to be careful," she warns. "I was with a friend and the 'Halloween' ring tone went off. Before I checked who it was, I said, 'That's just some pain in the ..."

It was her friend's husband.