Gentlemen may prefer blondes, but a newly single Diddy isn't about to limit himself to just one hair hue. Since his recent split with capricious longtime love (and mother of three of his children) Kim Porter, he's apparently been an equal opportunity flirter. According to People, the meticulous multihyphenate was glued to the side of a mystery blonde Friday night in Baltimore where he was hosting the "All White Diddy Affair." "They were friendly," a bystander tells the mag of the rapper and his minidress- and stiletto-clad companion, who got to know each other while quaffing a $500-a-bottle Veuve Clicquot champagne. "He was dancing," adds another eyewitness. "And so was the girl with the blonde hair -- she was dancing [in front of him]. She was enjoying herself too." A few days earlier, the New York Post spotted Diddy in the Hamptons "canoodling with a brunette in a cabana with three bodyguards blocking him from fans and paparazzi."

In related news, is Sienna Miller back on the market? The semifamous starlet, whom the tabloids linked to Diddy shortly before his bust-up (both have denied being anything more than pals), has supposedly been handed her walking papers by sometimes squeeze Jamie Burke, according to the London Sunday Mirror. "Things have been difficult for a while," a Burke insider gabs to the tab. "He is based in New York, she has been in London and they don't get to spend that much time together because they are both so busy ... They couldn't make it work, so they split. But they are being mature about it and leaving things open." Sienna, who was rumored to have called it quits with Jamie several weeks ago, recently told "Extra" that she has a "new man" (who isn't Diddy).

Hilary Duff has apparently worked through feeling "disrespected" over how quickly ex-boyfriend Joel Madden rebounded into the emaciated embrace of Nicole Richie. Seems the toothy teen queen has been looking awfully cozy lately with club promoter Frankie Delgado from MTV's "twentyfourseven" (no, we've never seen it, either). Not only were they hand-in-hand as they exited Hyde through the back door on July 12 (per TMZ.com), but they were also seen dining on June 22, clubbing on July 2 and cavorting in the sand and surf at a Malibu, Calif., beach bash on the Fourth of July (per People). "He was playing with her ring and then her bracelets," a spy tells the magazine. "Anything to get close to her." Or not. An insider insists their recent together-time is platonic, saying they're "really good friends, like brother and sister."

Meanwhile, is Hilary's big sister Haylie proof that the Hollywood dating pool is more like a murky puddle of stagnant water? She's reportedly been spending quality time with well-muscled C-lister Brody Jenner, who briefly dated the aforementioned Nicole Richie, who may or may not be knocked up by Hilary's ex, Joel Madden. According to People, Haylie and Brody looked thisclose during a recent night out at Los Angeles hot spot Hyde as they giggled and whispered in each other's ears.

Just four months ago, Shanna Moakler proclaimed she was once again "madly in love" with estranged husband Travis Barker, but their second honeymoon has come to an abrupt end, says People. "About a month ago, they separated again," a Moakler mole tells the mag. "She moved out. As far as she's concerned, it's over. She loves him, but it's one of those relationships where they keep trying to make it work but it doesn't." According to TMZ, the tattoo-festooned rocker and the top-heavy blonde, who waged a My Space-set war of words after they split in August 2006, are still working out custody of their two tots, moniker-challenged daughter Alabama, 1, and son Landon, 3.

Adam "DJ AM" Goldstein is spinning solo once again. The New York Post reports the ex-boyfriend of Nicole Richie and Mandy Moore has jettisoned model Jessica Stam, whom he was first linked to in March. "Jessica was extremely high-maintenance," a source tells the paper. "He didn't see her because she was always traveling, and when they were together, they would just argue."

We're not sure how one validates a fledgling romance, but the self-proclaimed new woman in James Blunt's life insists they're bona fide. A "holistic therapist" named Mika assures the London Sunday Mirror, "It's official. I am James' girlfriend." And she could be a keeper -- seems she wouldn't mind hearing the Casanova crooner, who's been playing the field since breaking up with model Petra Nemcova, whine "You're Beautiful" over and over again. "How many girls wake up every day and get sung the most beautiful song in the world?" she tells the paper. "Things are going really well." So well, adds the Daily Mail, the pair plans to fly off to Ibiza for an extended sojourn. "James was talking about it at Live Earth," a source tells the paper. "He was saying how they will be there for August. He has introduced Mika to his parents and it's gathering momentum."

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