[a_e_k]

I'll second your first point about hard copies. It's one thing to skim a PDF on the screen to see if it might be worth my time, but if I really want to grok a paper I'm marking up a hardcopy.

This has also made me appreciative of authors who put in the effort to make sure that their graphs and diagrams reduce well to grayscale. Instead of referring to the red line versus the green line, they'll use labels, marks, different cross hatch types, etc. (Don't get me wrong, good color is still very nice to have too!) It's also led me to making it a point to print off drafts of my own submissions on a B&W laser printer and make sure that my figures and captions are still understandable. I expect that this makes it easier for any colorblind readers as well, whatever type of colorblindness they may have.