AJ Michalka | Latest News, Photos, and Videos

Zac Efron shows off his legs in a pair of short shorts for Miley Cyrus‘ Halloween party on Saturday (October 29) in Los Angeles.

The 24-year-old actor dressed up as a Reno 911 cop for the picture with sisters Aly and AJ Michalka, who tweeted the pic along with the caption, “Love our friends xo.”

PHOTOS: Check out the latest pics of Zac Efron

AJ dressed as the Queen of Hearts and Aly kept it vintage as a cigarette girl (FAKE cigs only!)

Also pictured inside: the sisters with Miley Cyrus, who showed off some nifty face paint.

• Aly and AJ Michalka‘s stalker pleads not guilty – TMZ
• Ashley Tisdale is hard at work filming Sharpay’s Fabulous Adventure – Just Jared Jr
• Prince Harry and Chelsy Davy are still together! – Us Weekly
• Justin Timberlake promotes a new women’s fragrance – Lainey Gossip
• Amanda Bynes is flirty for Maxim – The Superficial
• Daniel Radcliffe wept during last day of Harry Potter shooting – MTV Movies
• Eminem opens up about his ‘recovery’ from prescription addiction – Access Hollywood
• Suri Cruise looked ready for a nap bundled in a blanket around NYC – Popsugar
• Justin Bieber wants a girl with brains! – theFABlife
• Khloé Kardashian buys a $400,000 celebratory gift to hubby Lamar Odom – E! online
• Miley Cyrus is stylin’ in NYC – Trendmill
• Padma Lakshmi: Everything is better with Krishna around – OK
• Paula Abdul turns 48! – PCN
• Leona Lewis splits with her boyfriend of nearly 10 years? – Splash

Zac Efron celebrated his 21st birthday party at Pace in Hollywood on Saturday.

HSM pals Vanessa Hudgens, Monique Coleman and Ashley Tisdale (with boyfriend Jared Murillo) were around to celebrate. Zac‘s Hairspray friends Brittany Snow and Amanda Bynes also came out to celebrate.

Pals Aly & AJ Michalka and Michelle Trachtenberg also attended the big birthday bash. After Pace, they took the party to Chateau Marmont.

Looks like Zac received a lot of alcohol for his birthday–Ketel One Vodka, Jack Daniels Whiskey and Grey Goose Vodka.

On Tuesday, the cast of High School Musical 3 will dance their way onto the TRL studio to share what Senior Year is like. On Wednesday, don’t miss Zac on ABC’s Good Morning America. The HSM3 cast will also guest on CBS’s The Early Show on Friday.

15+ pictures inside of Zac Efron‘s 21st birthday party… More Here! »

Pop duo AJ & Aly Michalka leave Anastasia Beverly Hills Salon in Los Angeles, Calif. on Wednesday.

Aly, 19 and AJ, 17, are growing up fast, shopping for some lingerie during their trip!

Both sisters are involved in the campaign to “Erase MS”. Check out the duo sporting their orange shirts!

40+ pictures of AJ & Aly Michalka on a shopping spree… More Here! »

Pop duo Aly Michalka and AJ Michalka model their Tommy Hilfiger-designed orange t-shirts to support the Nancy Davis Foundation for MS.

May is MS Awareness Month and the organization has partnered with a number of retailers to sell items in the signature MS orange – symbolizing hope. Proceeds will go towards educating the community and funding MS research.

Leather bracelets by Alexandra Knight and wallets/peace bracelets by Tommy Hilfiger are also being sold.

For more information, please visit EraseMS.org.