The world of acting is a tough cookie to crack, and even when you're a huge Hollywood star, you still have to audition for the parts you want.

I guess we all start out somewhere.

These actresses weren't always the glam performers they are now. And these tapes show their humble beginnings in the industry.

Rachel McAdams
In my opinion, Rachel is a really good actress and this tape proves it. She might only be known for her smooshy chick flick roles (and for being bitchy Regina George in Mean Girls), but I think she can do so much more.

Natalie Portman
When she was just 11 years old, Natalie played a little girl whose family is assassinated and goes to live with the gun for hire next door in Leon: The Professional. If you haven't seen it yet, get a copy ASAP. She's brilliant. They should have just given her the Oscar then.

Selena Gomez
Before she was Justin Bieber's on-again/off-again girlfriend and pop star, she was just an 11-year-old girl trying out for Disney's Wizards of Waverley place.

Jennifer Garner
She kicked ass in Alias, but Elektra wasn't the best movie of her career. However, it did help cement her superstar status.

Evangeline Lilly
I'm sure I'm not the only one who was completely confused by the plot (and the ending) of Lost. But, over all, it was a great show. Here's how Evangeline got the part of Kate.

Gabourey Sidibe
The amateur actress was pushed into the audition for Precious by friends, and landed up not just getting the part and doing a fantastic job of it, but an Oscar nomination for best actress too. Even her audition is powerful.

Ellen Page and Olivia Thirlby
They played BFFs in Juno - a movie about a quirky teen outcast who falls pregnant and has to deal with the repercussions.

Sandra Bullock
We're not sure which role Sandy B is auditioning for, but she's definitely got the Snooki persona down pat.

Emma Stone
Her break through role in Easy A illustrated her chops as a comedy actress, but also showed the world that she was more than just a pretty face. This video shows a self-taped audition for the scenes where her character, Olive, is speaking into her webcam.