The Diary: Serpentine Gallery Summer Party; Michael Winterbottom's The Killer Inside Me; Jojo Moyes; Billy Collins; La Divina

Boy in da Serpentine

There was an added surprise bonus for anyone who shelled out for the ultimate party of the season, the Serpentine Gallery Summer Party. Amid the champagne-swilling, the games of ping pong with championship players set up by the gallery, and the right to roam among a guest list that included Stella McCartney, Erin O'Connor, Peter Blake, Grace Jones, Rhys Ifans, Vivienne Westwood, Tracey Emin and the Chapman brothers, Dizzee Rascal turned up to perform a "surprise secret gig" under Jean Nouvel's newly erected, bright red pavilion. Dizzee's performance, which marked the gallery's 40th anniversary, was arranged by the manager and promoter Raye Cosbert. A lot of the exquisitely dressed European heiresses and billionaires were also seen having their heartbeats recorded in the French artist Christian Boltanski's interactive installation The Heart Archive.

Pulp friction

Michael Winterbottom's latest film, The Killer Inside Me, has ruffled feathers for its high level of on-screen violence. The angriest critics have levelled accusations of misogyny at the director on the grounds of a graphic and painfully extended scene in which Jessica Alba is beaten to a pulp by Casey Affleck. But Winterbottom tells me that he is greatly irritated when people mistake fiction for documentary. If one is going to address violence against women in a movie, it is pointless to flinch from it, he suggests. "It's a film that deals with violence against women. It's a noir, a fictional film, set in a fictional world. He [the psychopath played by Affleck] is not a hero. There is no way you could watch the film and think it was encouraging violence. It's frustrating talking about it. The criticisms imply that it is a semi-documentary, not a fictional noir." The director also says that he is perfectly satisfied with his documentary film rendition of Naomi Klein's book The Shock Doctrine, despite the fact that she first came on board the project and then distanced herself from it. He says he was not trying to get away from the book but had to reduce its scope for cinema. It is due out on DVD on 19 July.

Jojo is a loan star

The award-winning writer Jojo Moyes, whose The Last Letter from Your Lover is out this week, tells me she supports Kiva, an organisation that invites those who can afford it to lend money to people in the developing world, so that they become less reliant on loan sharks. Moyes says she's subscribed for three years, and has loaned $25 to a woman in Vietnam so she could buy a pig, and to another woman who needed to buy supplies for a tiny shack selling cans. "It's great, you get to see pictures of them. You have to be prepared to lose money but I've never lost any, and you can see who else has loaned money to that person from across the world."

No rhyme or reason

The former American Poet Laureate, Billy Collins, who headlined at the Ledbury Poetry Festival this week, tells me there's a great difference between the prestigious role in the US and in the UK. Some in America, he says, are awarded it purely as an "honourable lifetime achievement award", rather than to fulfil any active duties. W S Merwin was awarded the title last week. "He lives in Hawaii and has a semi-reclusive life," says Collins. "He's not banging the drum for poetry." That's not meant as criticism, he adds, it merely highlights the difference in duties. "There are some young (American poet laureates) who just worked on their smoke rings." The industrious Carol Ann Duffy comes out looking all the more hard-working in comparison (as does Collins, who led various high-profile, high- school campaigns for poetry).

Divina intervention

An opera is to take place on board the legendary super yacht Christina O, in September, departing from Monaco, I'm told.

La Divina will interweave the tragic story of Maria Callas's life and love affair with Aristotle Onassis with her signature arias performed by the sopranos Nelly Miricioiu, Claire Rutter and Mary Plazas. Guests on board the cruise yacht will follow in the footsteps of Sir Winston Churchill, President John F Kennedy, Elizabeth Taylor and Marilyn Monroe, and will no doubt pay a pretty penny.