Encouraging users to give you feedback is not that easy, if you are designing a blog you should make the posting procedure as simple as possible. Otherwise many users will get impatient and leave without writing any comment.One example of complicated design could be the SEOmoz blog. The content of this blog is very useful but if you want to post a comment a pop-up is prompted and users are asked to login or register.

Note that the Register button is not visible, users must drug the window (although that might depend on the screen configuration). This adds one more usability flaw to this interface.Then another floating window to post the comment:

Techcrunch, the famous blog, has a much more practical solution for posting comments. I will go for simple solutions, allowing users to post straight away.
