Keira Knightley and Sienna Miller have set up a "nerdy" book club.

The two actresses - who became friends when they starred in Dylan Thomas biopic "The Edge of Love" - prefer to stay in and enjoy quiet hobbies rather than hit the showbiz party scene.

Sienna revealed: "We swap books. I went to Keira's house for dinner and we talked about books and swapped some. We play cards and do newspaper crosswords together.

"She's learning the flute at the moment and I'm learning the piano. I mean we are really quite nerdy."

Despite happily confessing to their love of unglamorous pastimes, Sienna is worried about how Keira will react to her letting their secret slip.

She said: "Oh god, she's going to kill me now. She's not a nerd. I can be. No one will believe it anyway."

As well as sharing a mutual love of sedate activities, 24-year-old Keira and Sienna, 27, also live their lives by a common rule - ignore what your critics are saying.

Sienna explained: "We keep ourselves afloat if things happen in the media that are hard to deal with, or the awful temptation to Google yourself comes up, and just being mortified about what people write about you. She'll phone me up and say, 'I'm thinking about doing it,' and I'm like, 'I am too... don't do it, don't do it!' And we'll kind of talk each other out of it. It's hard sometimes to not want to know what people are saying behind your back and to ignore certain things that are being written."

(China Daily/Agencies, April 2, 2009)