The Dark Knight again topped the American box office charts this weekend, taking a further $26 million and taking its total to a staggering $441.5 million - putting it on course to be the second biggest domestic grossing film of all time, behind only Titanic. The stoner action/comedy Pineapple Express coined a solid $22 million for the weekend and over $40 million since its release on Wednesday - rendering it another hit for new comedy prince Seth Rogen. Other new opening Sisterhood of the Traveling Pants 2, took in $10.8 million for the three day weekend, but an impressive $20 million since its bow on Wednesday. Elsewhere, the two sleeper hits of the summer are Mama Mia and Brendan Fraser flick Journey To The Centre Of The Earth In 3D. Both have suffered slight declines since their respective releases, and have totals that stand at $104 million and $81 million.