Watch out, Sandy, Bowzer's at the dance! Okay, this isn't the same princess-kidnapping Bowser. This Bowzer is part of the classic rock band Sha Na Na, who stars in Grease as Johnny Casino and the Gamblers. That's a good band name, but it doesn't roll off the tongue as well as Sha Na Na. (Source)

Jeff Conaway (Kenickie) wasn't always second banana. In the Broadway production of Grease he played the first banana, Danny Zuko. And while he may not have ended up with Sandy in the movie, he did end up with Sandy's sister. Conaway was married to Olivia Newton-John's sister, Rona, in the early 80s. (Source)

When Sandy and Tom dine at the diner, you might notice a blurry poster behind them. No, the producers didn't overlook some sexually explicit diner art. The poster is an ad for Coca-Cola. After agreeing to give product placement to Pepsi (see the case in the background of "Hopelessly Devoted to You"), the offensive Coke poster had to blurred out in post-production. (Source)

You've heard of waiting tables while trying to get a big break in Hollywood? John Travolta's sister, Ellen, is waiting tables as her big break. The star's sister is a diner waitress who watches National Bandstand on TV. (Source)

In the DVD commentary, Patricia Birch says that the "Hand Jive" originally had a more, um, risqué title and lyrics. If you can't catch our drift, put your mind in the gutter and consider this line: "I could barely walk when I milked a cow." (Source)

Matilda loves Grease. Mara Wilson, who played Matilda, wrote an essay about always seeing herself as "a Sandy in Rizzo's clothing." (Source)

Grease's director, Randal Kleiser didn't like the title song, "Grease," because it didn't "fit the fifties style musically or lyrically." We think he's right, but it's still an amazing song, and it reminds us that the movie has its feet in two decades—the 50s and the 70s. (Source)

One freaky fan theory surfaced that said maybe the whole car-flying-and-everything-is-perfect ending is a little too far-fetched to be real. And apparently that means they had to jump to this conclusion: Sandy was dead the whole time, and the movie is the dream she had in a coma before she died. Yeesh. But hey, Sarah Michelle Gellar believes it, so it must be true. (Source)