Wherefore tweet thou?

Shakespeare's Romeo and Juliet is being played out over five weeks via Twitter. Is it a step too far or a way to modernize a classic?

"OMGGGG! Me + Gorgeous boy in the mask = SNOGGGGG!!!! Omg best thingggg!!! omg omg omg!!!!!!!" It's the kind of update posted online by excitable 16-year-old girls across the world. Not exactly the finest example of literary prose. But this is exactly how two of the most lyrical characters ever created - Shakespeare's star-cross'd lovers Romeo and Juliet - reveal their ill-fated relationship in a new internet-based update of the Bard's enduringly popular play.

The location of this "best thingggg!!!"? A party for which Juliet sent out invitations via Facebook. We even know the soundtrack to the fun - naturally, it's all streamed through Spotify. Welcome to Romeo And Juliet for the 21st century. Such Tweet Sorrow is a collaboration between the British production company Mudlark, Channel 4's innovation fund 4iP, Screen West Midlands and the Royal Shakespeare Company.

Steadily building an impressive audience (Juliet now has nearly 6,000 followers around the world), you can either choose to be friends with all the characters and their stories via Twitter, just your favourites (Mercutio's ironic links to classic YouTube clips on his deathbed have been a real highlight), or catch up with the whole story on the website as it runs in real time over five weeks. The inevitable accusation is that the project, with all its txt spk, is somehow tarnishing the glorious language of Shakespeare. Mudlark's Charles Hunter audibly "lols" at that.

"Shakespeare's language is the medium for getting across his stories, and it's fantastic," he admits. "But it's not sacrosanct. And Such Tweet Sorrow isn't about chopping up Romeo And Juliet into chunks of 140 characters or less, it's about telling the story in a modern context, and letting that run the rhythm and the feel of the piece." "And anyway, the story of Romeo and Juliet has been around since the third century," adds James Barrett, who plays Romeo.

"Shakespeare updated it for his time. So in a way, we're doing the same as him, but for a 21st century audience." It might sound odd to say Barrett "plays" Romeo - after all, the stage is a virtual one, and the lines are typed into a laptop - but in fact, Barrett has found it just as enthralling as "normal" acting, and in many ways it's a straightforward theatrical production. There is a script: the writers Tim Wright and Bethan Marlow supply a grid split up into days so the actors can see what they are meant to be doing.

The RSC supplies the director, oxana Silbert, whom Hunter says was inspired to do Such Tweet Sorrow by the Alicia Silverstone film Clueless. In that film, tellingly, Jane Austen's Emma is given a completely modern update without disregarding the gist or the heart of the story. "It's actually more involving than just turning up for a performance every evening," says Barrett. "When you're tweeting constantly for weeks on end, you're honestly always thinking what Romeo's doing. So it genuinely does mean you live your day through him. You're 'in role' 24 hours a day.

"And because the tweets aren't all specifically written by the authors, you're also in this strange world where you are thinking like them constantly. It's a very new way of working for all of us." And what's excited everyone involved in the project is how the audience - or in Twitter parlance, followers - have participated so enthusiastically. This isn't just a passive experience; a page was set up on blogging platform Tumblr by fans to "save Mercutio".

Barrett likens the experience to "being heckled after every line on stage". "It's scary like that. Imagine coming out of a stage show and every single person grabbing you afterwards to tell you how you did! But seriously, Mercutio tweeting that he's getting ready for the party at the time of day when 'real' people are doing the exact same thing is done for a reason: it brings a whole new sense of realism to the piece.

"And then to upload the party playlist onto Spotify, so people can get the atmosphere of the party, just encapsulates this idea of an online community involving themselves in a story." Romeo goes so far as to take a sneaky cameraphone picture of the girl who steals his heart and put it online. There are, immediately, comments telling him to introduce himself. So could such interaction change the direction of the story?

"It's interesting you should say that, because I was having this exact same conversation with people who didn't use Twitter last night," says Hunter. "They were intrigued by the possibility of the story changing, but it can't really. I'm pretty secure about that. "There's an inspiration here from narrative-led video games where a story might branch off depending on your choices, but in the end it always comes back to the same place. So we have to have an authorship to ensure the story is satisfying and makes sense.

"But the followers have definitely lent a texture and a certain amount of character and language to it. And talking to some of the actors, their followers have enabled them to understand their characters more deeply." Barrett is one of those actors, and he thinks Such Tweet Sorrow has made him see Romeo in a whole new light. With the language stripped away, the essence of the characters is suddenly crystal clear, the story sparklingly vivid.

"What I've really got from doing this, and tried to get across, is that he's just a young lad," he says. "He's impulsively running away to get married to his first love, without regard for anyone or anything else. And that becomes much clearer when the followers tweet responses like 'what are you doing!'. "Essentially his behaviour is a bit ridiculous. I don't know whether that stands out when you see other productions of Romeo and Juliet."

You also don't get audiences shouting out pleas for the safety of Mercutio in the theatre. But as the blog on Tumblr shows, anything is possible in Such Tweet Sorrow. "I did love that blog," admits Hunter. "I mean, he's clearly unsaveable, but it made it quite sweet and poignant. The actor who plays him told me he was genuinely moved by the whole thing. "It's very gratifying to see things like that, that people obviously understand that it has got something concrete and meaningful behind it. It's not just some girl going 'OMG!!! I think I'm in lurrrve'."

Well, it is sometimes. Follow the story at www.suchtweetsorrow.com.