lukaiser

ILAnnotations allows you to select a text in a blog post and add your comment to it. 
The plugin uses the standard comments engine of WordPress, so all other comment plugins should work just fine with it. 
Shortcodes are used to mark the highlighted text. This allows you to still edit a post and move stuff around without losing the annotations.

ILAnnotations

Annotate any text in a blog post and add a comment to it.

Achilles_sm

Larry Kokoszka

Rollerblade is a tool that you can use to easily create issue reports and tickets for your team, right from an in-line interface on your WordPress installation.
Here’s the Demo: 
http://www.youtube.com/watch?v=s6NST466XTg
It’s the perfect solution for developers, designers, teams, QA professionals and anyone that needs client feedback in a documented and easy to understand way.
<h3>Support</h3>
Our support portal is located at http://rollerbladeapp.com/support.

Rollerblade

Pros:
- The concept is very interesting.
Cons:
- Requires a browser extension, and uses negative reinforcement to convince you. "Install, or continue to use Bad Screenshots".
- Assumes you are on a large screen. Small screens are out of the question.
- Registering a domain to your account is a little odd and requires setup on both ends (account and site).
- WARNING: Account signup sends your password in plain text. (Eeek!)
Neutral:
- Requires an account with their service, as tickets from all of your domains are stored in a central location. (May or may not be helpful, based on your situation)
- Reporting and Analysis require premium upgrades.



Interesting Idea

Rollerblade - a dead simple way for your clients to leave visual feedback on your WP site, creating information-rich tickets for you to track reports.

ILAnnotations vs Rollerblade