I personally don't care that much about most articles being printable, but if you're making any kind of material that is supposed to be studied, please, please make sure it's properly printable. Doing research / studying a topic is something that is still infinitely easier to do on paper IMHO.

Having said that, does anybody know a decent web-based app for researching stuff? What I definitively need is:

* Ability to have a collection of related articles in one place

* Simple list of bookmarks that link to a specific part of the text.

* Highlighting in different colors

* Adding comments to a page that are _easy_ to view. Preferably in a sidebar next to the page or something.

* Adding links to external sources interactively to the document

* The ability to write a summary of the article

I've searched before a few times, but I've never been able to find something that had all the above and, more importantly, properly integrated those features.