IF YOU DON'T want to join the hundreds of SEPTA riders screaming "iYiYi! My iPhone!" as their smart handhelds disappear into the smarter hands of quick-grab thieves, you better heed the urgent warnings now blasting over public-address systems on subway and El trains.

To save your Droid from the void, keep your smartphone hidden while riding, SEPTA Transit Police Chief Richard Evans told the Daily News.

Most of last year's 415 thefts and robberies committed on the Broad Street Line and the Market Frankford El involved smart- phones, e-readers and laptops, he said. That kind of crime has trended dramatically upward since the 182 thefts and robberies in 2008 to more than double that number during the 58 million passenger trips taken last year.

The highest crime areas are between City Hall and North Philadelphia on the Broad Street Line, and between Huntingdon and the Frankford Transportation Center (Bridge/Pratt) on the El.

"Most electronic-device crime involves teens and young adults between the ages of 16 and 28," Evans said, adding that SEPTA's 228 transit officers work overlapping shifts between 1 and 4 p.m. - prime time for thefts and robberies on the subways.

Evans said that riders should call the transit-police emergency number - 215-580-8111 - to report a crime (on someone else's phone, presumably). There are also red emergency buttons in all trains and yellow emergency call boxes in all stations.

Evans said the transit police hope to bring the theft/robbery numbers down by:

* Operating out of in-station headquarters in each of SEPTA's eight transit zones, which "gives officers a sense of ownership of their patrol area and a sense of familiarity with the riders . . . "

* Making SEPTA's three three-officer antiterrorist teams in black SWAT-style uniforms as visible as possible in the areas where most thefts/robberies occur.

* Using in-train warnings and distributing fliers warning riders that to a thief, smartphones are the same thing as $100 bills. Riders are cautioned not to use their devices near subway car doors or when leaving the station.

"If I can get the passenger who is texting away from the door and into an inside seat, chances are that passenger's cellphone won't be snatched when the door opens," Evans said.

"Standing near the doors and texting is comparable to standing there with your pocketbook open and hanging from your shoulder." It's an invitation to a thief, Evans said. "We will get a handle on this disturbing trend eventually," he added.

"It would help if riders only use their cellphones out of dire necessity. Use your cellphone wisely, use it discreetly, so it's not out there for the plucking."

Contact Dan Geringer at 215-854-5961 or geringd@phillynews.com, or follow on Twitter @DanGeringer.