Interested to hear from your readers on your blog? Here is an innovation call SpeakPipe. It is currently free to use and still in Public Beta. You will get a pinned widget on your blog where readers can use it to leave a message.
I did not install it on my site yet. As mentioned, the service is free at this moment but will be chargeable once it is officially launched. Each voice mail is up to 5 minutes and you will receive them on SpeakPipe inbox.
The widget is quite versatile. You can placed it on the left or right. Currently, it is supporting WordPress, Blogger, Tumblr and Joomla platform. If you are not on any of them, you can still copy and paste the HTML code.