Taking notes on powerpoint PDF slides

My school provides students with PDF versions of the powerpoint slides that the professors use in lecture. Many students print them out and take notes on them, a system which I dislike because that wastes paper, and I like to keep my notes organized on my computer. I currently take notes using Microsoft Word's notebooks which is okay, but I end up rewriting things that are on the slides. Sorry for the long winded intro, but my question is are there any programs available that would allow for the addition of texts to the PDFs. I know how to do it with Adobe Software, but I was hoping that someone could clue me into a simpler solution for in-class note taking. Adobe's programs are all have more features than I need on a daily basis, I would like a program simpler and more streamlined.

Thanks in advance,

Justin

Audio Tags

Thanks BruinEcon. I forgot to add I would also like the program to be able to record audio and add audio tags, but that might be too much to wish for.