ask_rave is a question and answer script, designed with simplicity, but has interesting features and looks quite good too. Themes allow you to intergrate it with your site, either by using your own headers and footers, or using the transparent theme for i-Frames. Email alerts tell you instantaneously when you get a new question to be answered. Emoticons add a bit of colour to your questions and answers. You can also add your own easily! It also doesn't require a database. As it's flat file, you only need a webserver with PHP to run it. No more messing about with MySQL values! Did I mention it's free?