Skribit widget can be embedded easily into any blog and allows your readers to post and vote post suggestions. There is a limit to 5 suggestions for the free version of the widget though, but that should be enough. A nice feature is that the users must not have a Skribit account to be able to suggest/vote (unless other specified by you).
Skribit widget comes in two flavors: one which can be directly embedded into your blog (see the image at the beginning of the post), and another one which is just a suggest button which, if clicked, opens up a window (using jQuery I believe) where the user is able to vote or post suggestions (see image below).
Both widgets can be easily customized once you register your free account and for even more customization, you get a list of the CSS elements in the widgets (for advanced users).
