Adobe Reader

I wish Adobe Reader would have some type of highlight function. I'm currently going though a journal article which I'll be using for my last ever undergrad essay. There a lot of good stuff here but since this is the first material that I've reading for this essay I'm not sure what I'll be needing for the final essay. I think the only reason I print out articles and such is because I'm able to highlight it and go though the article when I come to writing. Plus lately I've been doing this color code system with my highlighting. Green means great stuff, will put in my essay no matter what. Blue is good stuff that might make it in depending where I take my essay. Orange or hot pink, is interesting and could be used for something but probably not this essay.

Anyone know of some add-on that you can dl and use in adobe?