People here (southeast USA) like to ask this question as they are walking by. There is absolutely no way to answer in an honest way, you just have to say "Good, good." or something like that. Furthermore, since you're walking by it's still awkward even to say "Good, you?" I've always found it really weird. If you just want to say hey, say hey! Hello. Greetings. Salutations. Don't ask me a question as you're walking away. :v