Amanda Woods (Cameron Diaz), the owner of a prospering advertising firm that creates movie trailers, lives in Southern California. Iris Simpkins (Kate Winslet) writes the popular wedding column for London's Daily Telegraph and resides in a charming cottage in the English countryside.
Though Iris and Amanda live 6,000 miles apart, they are in exactly the same place: Just before Christmas, Iris and Amanda decide to take a needed break from the men in their lives — and neither is much in the mood for a nostalgic chorus of "Auld Lang Syne."
Amanda, wanting to get out of town for the holidays, stumbles onto an internet site that specializes in home exchanges, and finds Iris' English cottage to be the perfect antidote to her troubles. On impulse, Amanda and Iris agree to crisscross continents and move into each other's homes for two weeks.
Iris lands in Los Angeles on a spectacularly clear day warmed by the gusts of the seasonal Santa Ana winds. Not long after she arrives at Amanda's Brentwood home, she is befriended by Arthur (Eli Wallach), a noted screenwriter from Hollywood's Golden Era, and Miles (Jack Black), a film composer who works with Amanda's ex-boyfriend.
In England, where it is anything but balmy, Amanda is just settling into the cozy solitude of the snow-covered Rose Hill Cottage, when Iris' handsome brother Graham (Jude Law) comes knocking at the cottage door.
In an unexpected turn of events, both women discover that the best trips are the ones where you leave your baggage behind.