This movie is sweet - not cloying, just warm-spirited and kind. I found it only mildly funny, and the premise *is* wildly improbable, but the characters are so charming (especially Minnie Driver's) that they had my full attention right from the beginning, and soon had my affection too.
Bonnie Hunt has done a great job in her directing debut, and a good job with the writing as well. I highly recommend this movie and will see it again, I'm sure.