Does anybody know if the PDF version Og has any restrictions (like DRM or unprintable)? I'm trying to decide between buying the PDF or buying the regular version. If the PDF version has restrictions, that really kills the advantage for me--I move around a lot (travel, school, etc.) and want to be able to print it when I'm away at school, access it from my email when I'm abroad, etc. I was really pleased to see it offered in ebook format, I'm just worried I won't get what I'm expecting.