Posted Dec. 22, 2008

Fortunately, the squeals emanating from a Los Angeles hospital on Friday had nothing to do with needle jabs or other painful procedures. Instead, they were caused by the appearance of Zac Efron, who turned up at the Mattel Children's Hospital at UCLA to spread some holiday cheer (and perhaps generate a bit of holly jolly publicity).

Zac visits kids at the Mattel Children's Hospital in Los Angles on Dec. 19. (©WireImage.com)

Us reports the dreamy-eyed "High School Musical" heartthrob spent two hours at the medical center greeting seriously ill patients, posing for pictures, signing autographs and handing out toys (the $10,000 worth of Tickle Me Elmo dolls, art supplies, board games, "HSM" offerings and other fun stuff was provided by -- promotional alert -- Gifts.com).

Related: Brad Pitt's Make It Right and other celebrity's charities

"He really spent time bonding with each of the children and their families," an eyewitness tells the mag. "The kids were smitten and beaming from ear to ear. ... Zac was super gracious and could not have been more kind and truly happy to be there."

In related celebrity do-gooder news, a chance encounter on a plane has brought out Penelope Cruz's altruistic side.

Penelope hits the Gotham Independent Film Awards in New York on Dec. 2. (©Retna Ltd.)

The London Telegraph reports the actress got to chatting with a seatmate on a flight from Madrid to London earlier this year and learned he was a volunteer transporting bone marrow for Britain's Anthony Nolan Trust.

Cruz, who's been in London filming the musical "Nine," offered her help in promoting the charity's bone marrow registry and recently met with an 8-year-old leukemia patient named Joe Cawse, who's been searching for a matching donor for three years.

"One suitable donor could save his life. Imagine if it was your brother, mother, cousin or friend, and with just one step, you could save their life," urges Cruz in a statement encouraging people to join the registry. "Wouldn't you do it?"

For Joe, the meet-and-greet with Penelope was pleasant, if perhaps a little confusing.

"They talked about Christmas and what he wanted to get as a present. He didn't know for sure who she was, but we told him she was famous," his mom tells the paper. "At the end, he said that he thought she was lovely and very pretty."

Alas, not everyone is so complimentary of Cruz.

The London Daily Mirror claims that mega-producer Harvey Weinstein was most displeased when she turned up a wee bit late for a screening of Woody Allen's award-bait film "Vicky Cristina Barcelona" last week at London's Mayfair Hotel.

A source says that when Weinstein learned the Spanish looker was heading to her suite to change before hitting the event, he bellowed, "Tell her to get her [bleeping] a** here right now!'"

Tom arrives at a UCLA benefit in Los Angeles on Dec. 2. (©AP)

And finally, Tom Hanks is doing his part to make sure reading remains fundamental.

According to the New York Post, the benevolent A-lister recently used his fame to drum up business for a struggling independent bookstore in Pacific Palisades, Calif.

With bodyguards in tow, the "very friendly" Oscar winner reportedly sat at the back of Village Books and signed anything that customers handed him.

Hanks was due to put in a two-hour appearance, but he hung around for an extra half-hour to make sure he inked his John Hancock on every last tome (sample signing: He wrote "Hit the road!" on an offered paperback copy of Jack Kerouac's "On the Road").

The store's owner expressed her gratitude to the star, telling the paper that because of his efforts, "We're catching up on the rent."