In a modern rendition of Shakespeare's tale of star-crossed lovers, I'm playing Romeo to photographer John Stanmeyer's Juliet. A match made in Hollywood heaven, we are not. Fortunately, we're just virtual actors, and our alter egos on the video screen are animated versions of the doomed couple from Verona. This is interactive theater, a fusion of movies and role-playing video games that could be ready for your neighborhood cinema within a decade. It's a natural evolution that combines two forces at work in this age: celebrity culture and the Internet revolution. In interactive theater, the audience becomes both actor and director, reading the lines and calling the shots. Who needs Leonardo DiCaprio to play Romeo when you can take on the role yourself?The cyber-age drama that John and I perform is a 20-minute production created by Naoko Tosa, a scientist at telecommunications research company ATR. Tosa, 38, has also produced works of video art since the 1980s. Her interactive theater is an attempt to explore the commercial possibilities of her research. (Tosa is hoping someone will provide funding for a permanent exhibition so more people can try out the technology.) This Shakespeare picks up the story of Romeo and Juliet after they've died. They're in Hades now, guided by a pesky narrator and visited by ghosts of long-dead friends and relatives. The pair have lost their memories, along with their fashion sense. They wear sleek body suits and punk hair cuts and wander aimlessly from tatami rooms to moonscapes to a dark cave.Tosa started working on ways to make her art interactive in the early 1990s when she created a clever character called Neuro-Baby, an animated infant that cries, coos and pouts, among other activities, depending on how viewers speak to it. It doesn't matter what words you use, but rather your tone of voice. So, coochie, coochie, coo, if delivered like a drill sergeant, will make Neuro-Baby scream. Usually, communication with computers is logical, says Tosa. I'm trying to make it more emotional. With Neuro-Baby and another project, an interactive poem called The Muse, Tosa has tried to quantify the emotional component of communication. She graphs emotions-anger, surprise, disgust, joy and fear-and attaches facial expressions and voice intonations to them. The idea is to make machines better able to communicate with humans, not just by comprehending vocabulary and responding in kind, but by understanding the feelings behind the language. In the Shakespeare simulation, John and I strap on thick, vinyl vests with wires and sensors. We wear earphones, microphones, magnetic sensors and devices that vibrate to cue our lines. We stand in front of a large, curved screen, on which the animated characters of the Montagues and Capulets appear. We're given a choice of lines to speak; what we say-and how we say it-determines what happens next. There are 400 possible scenes we can stumble into, and our movements control the actions of the video figures. If John and I mimic an embrace, for example, Romeo and Juliet hug on screen. Like puppeteers without strings, we can also move our arms and hands to manipulate Romeo and Juliet so they touch the other characters on the screen. And since this enterprise is geared for the video-game generation, there are battle scenes in which we can fire laser-like bullets from our arms. Somehow, I manage to knock off Juliet's head, a tragedy that Shakespeare could not have foreseen.Juliet! Run! I plead as Paris, outfitted like the Terminator, suddenly appears to woo Juliet and harass Romeo.Romeo, don't be such a coward! John cries back.I want to make peace, not war, Romeo replies.I just want to go shopping, says Juliet.Romeo is kind of wimpy, so I start choosing tough-guy lines, like, Let's fight. Right here. A few scenes later, Paris is cowering in a corner. Juliet seems to like the new, more assertive Romeo. Somehow she gets her head back.The thespian adventure is enjoyable escapism, and it is interesting molding the characters into what we want them to be. In the end, though, I have to admit grudgingly that Leo probably makes a better Romeo than I do. And (sorry, John) Claire Danes is definitely a better Juliet.