"The Grass is Singing," Doris Lessing

Picked this up after reading about it on "Eve's Alexandria" and read it all in an afternoon, which is the best recommendation any book can have. A wonderful exploration of boredom, frustration, societal pressure, and emotional cruelty, although it's not a "man and woman overcome cultural boundaries and make sweet love until Society ends it" sort of book - the interracial relationship really only develops in the last part of the book and is basically the logical end to a series of choices on the part of a woman who ends up with very few choices to make.

Which might be disappointing if you picked up the book based on a cover like this.