Jennifer Anniston wants to have a kid, so she decides to implant and raise one on her lonesome. Jason Bateman is her friend. He accidentally becomes the father of her child, pretty much without either of them realizing it.
If you can get past the first half of the movie and the constant sex-talk, (not that you should be proud of yourself if you can,) then the movie levels out and you can sit back and laugh at the few funny parts.
It's not really worth a rental. But it's not horrible. I wouldn't even call it bad. I wouldn't even call it meh. I'd call it... okay, or something. But I'll probably never watch it again.