I have set up a website and want people to post feedback on changes they would like to see. I'm looking for an app they could either send email to and it displays them for me to read and comment on or that I can link to on my site for them to post feedback. Ideally I'd like it to be free
Also: not exactly what the question was asking for, but olark allows you to see visitors on your site and interact with them in real-time. When you are offline, they can leave a message which is forwarded to your email. It also keeps some handy statistics of when visitors are on your site. They offer a very minimal free version, as well.
Another nice one is http://getsatisfaction.com/
We are using this for some of our products to get feedback and suggestions.