Grace (Minnie Driver) discovers the letter she had sent to say thank you for her heart on Bob's (David Duchovny) desk. The next day she tells Bob that she was the recipient of his dead wife's heart and then leaves for Italy. Bob follows her after a couple of days, tells her he loves her and the movie ends with Bob dedicating the ape habitat to the memory of his late wife, Elizabeth. Grace, Grandpa and all of their friends are in attendance.
Oh yes, at the VERY end, Sophie (the older waitress) marries Wally (the man who NEVER walked her home).