Crocheted... kidney bean?

Hi all, I need some help. I have a pregnant friend who I want to shower with crocheted gifts, but I've managed to restrain myself to just a few things so far. One of the things I really, really want to make is basically a crocheted kidney bean. (She's calling the little one Bean until she finds out the sex and gives it a proper name, but I get the feeling the nickname's going to stick.) Unfortunately it appears that not many people want to make crocheted kidney beans (can't imagine why) and I can't find a good pattern. I tried to make it up myself, but nothing came out terribly bean-like. I'm having trouble making the kink in one side while keeping the other side curved. Can anyone help me?