If you have a blog like using WordPress and you would like to enable comments to be automatically posted in you blog with out Administrator approval the you need to do the following.
Once you login as an administrator you need to go to the following area in WordPress:
Dashboard -> Options -> Discussion -> Uncheck the boxed labeled “An administrator must always approve the comment” and “Comment author must have a previously approved comment”
but its not working …
This article is little bit old and it did work in old version of WordPress. Why do you try using DISQUS like the one I am using in my blog. It just a plugin and it help with all the spam that WordPress sometimes does not have. The disadvantage is that all your comments will be stored in DISQUS and not wordpress database.