Here's how love letters are written, circa 2007.

A few weeks ago, Christopher Anthony was on a plane about to take off from Los Angeles. He began tapping out a cellphone text message to his girlfriend, Stacie Harb: "I love you, beautiful... Thank you for everything you do for me/us..."

A flight attendant firmly told him to turn off his phone, but he couldn't stop. "I need a kiss. I need your lips..." As the plane reached the runway, the 26-year-old banking executive tapped his final thoughts: "I just need you. Bye lover." He hit "send" and then the plane took off for Paris.

Ms. Harb now keeps his 37-word declaration in her phone's saved messages. "It was perfect -- short and sweet," she says. "It's not some drawn-out, 10-page letter professing his undying love. That would be creepy."

Love letters aren't what they used to be. While young correspondents have committed their deepest feelings to paper for centuries, the latest generation of lovers is coming of age along with new technologies that let them court each other on the run. The passionate essays penned on Valentine's Days past have morphed into bursts of instant-message affection. Confessions once sealed in envelopes are now dashed off in email. While romantics have bemoaned the end of the love letter for decades, the latest generation of amorous Americans is turning the language of love into shorthand.

The medium and message aren't the only things changing. As love notes go electronic, they can also go public -- posted online, or forwarded mockingly to thousands. Romantics with an exhibitionist streak post their missives online at sites like CollectiveExperience.org, where the tongue-tied can cut and paste just the right sentiment. Social networking sites offer shortcuts, too: At eCrush.com, a site for teens and young adults, some 2.4 million registered users communicate through prewritten lines that appear via drop-down screens. Popular choices include "OMG! You're so hot," "If looks could kil...