Remarkerbe is an intuitive, powerful and innovative webpage marker you ever want.
It is for those who love marking while reading. PKM fans especially!
It is easy to start by simply one click. Then you can select what you want to mark, and press a certain key to classify it as a key point, or a definition for a topic, or a answer for a question.
More details: http://remarker.be
Getting started: http://remarker.be/getting_started