front end post editing plugin

Hi,

I was wondering is there is a plugin that does the following:
(1) enable visitors to edit (update) a post.
(2) notify the admin when a post was updated by a visitor let the admin aprove or not the new version of that post.

To be more specific:
I would like let visitors be able correct any errors that may appear on the blog’s posts by having something like this at the and of all posts:
“Have you noticed any error (gramatical or techincal) on this post? Just click here to correct it?” Then the visitor updates the post and clicks an “Update” button. After this the post is not automatically updated on the blog (this may cause spamming behavior and we don’t want that) but the admin recives a notice of the update (within the admin panel) and decides wether as to aprove it or not.

I found this plugin: Front-end Editor but I don’t think it does quite what I’m looking for.

Can anybody help me please?

Thanks!