If you've had your fill of superhero and dinosaur flicks this summer, then check out "Entourage" now that Jeremy Piven, Adrian Grenier, Kevin Connolly, Kevin Dillon and Jerry Ferrara are reprising the roles they made famous on the HBO series.

It's a fun and funny inside look at Hollywood, and for celebrity watchers, chockfull of cameos by such notables as Liam Neeson Tom Brady, Calvin Harris, Jessica Alba, Pharrell Williams, Andrew Dice Clay, David Spade, Kelsey Grammer, Ed O'Neill, Warren Buffett, and Mark Wahlberg, among others.

"It's quite a difference from the pilot when it was impossible to get anyone to do it," Connolly, who plays Eric "E" Murphy, recalls, "[Back then] we were sitting around, 'Who do we know? Who can we call? Who will do this?' Because people are afraid of what they don't know. Ali Larter saved the day. We have to give her a shout out. Once the show went to series, it was a different thing, but to get a cameo in the pilot was a tricky thing."

Several years have passed since we last checked in on Vinny Chase's (Grenier) crew. Ari Gold (Piven) is out of the agent business and is now a studio head who greenlights a film for Vinny to direct and star in. Of course, loyal brother that Vinny is, he can't resist a little nepotism and gives his brother Johnny Drama a small, but pivotal role that can change his career -- if the film ever gets released.

"My character has probably changed the least amount," says Dillon, who admits to loving Johnny -- with all his trials and tribulations -- just the way he is. "He still is striving for the same thing. He wants fame, not so much fortune. I don't want him to change too much."

It's also a role that Dillon can relate to as Johnny experiences what is possibly the worst audition of his life. Not only does the director insult him, but when he is trying to perform his audition scene, everyone is watching something on their tablets that is making them laugh.

"I have been through many bad auditions," Dillon says. "I did one with Rhea Pearlman that was so bad. I smoked cigarettes back then. It was five flights down, so I ran down to have a cigarette and someone said, 'Hey, they're calling you.' So I ran to the top of the steps, I went in, and I was huffing and puffing and sweating. It looked like I was a nervous wreck. It was just awful."

Needless to say, Dillon didn't get the job, but what he does get are thanks from struggling actors, who come up to him and say, "I've had that happen to me. You stood up to them. I love you for that."

While "Entourage" is a bit of heightened reality as far as what life in Hollywood is really like, it is actually rooted in fact. Originally, the series was intended to be a fictionalized version of Mark Wahlberg's life [who was an exec producer on the HBO show and is a producer on the film], but when Grenier was cast in the role of Vinny, the character was changed to play to his strengths.

What didn't change was the sense of loyalty the guys feel for each other, and why having an entourage made up of long-time friends is important. It's the idea that when someone like Wahlberg makes it big,  the bottom feeders turn up, so in order to protect themselves, the newly minted celebrity wants to surround him or herself with people who were there for them when they had nothing.

As successful as the HBO series was, turning "Entourage" into a movie wasn't a sure thing. In fact, it took Wahlberg to light a fire under writer/director Doug Ellin to get the movie made.

"Mark was the one who was instrumental in motivating Doug and finding people who wanted to make the movie," Connolly says. "Mark has been real smart about when to get involved, when to let Doug do his thing, and when he needed to come in and be our closer. I think without Mark we wouldn't have done this movie."

"Entourage" creator Doug Ellin directed the feature film from his own screenplay, story by Ellin & Rob Weiss, based on characters created by Ellin. "Entourage" opens in theaters nationwide on June 3.