My childhood friend Joel wrote a great post on his blog Fun Joel's Screenwriting Blog about the Margins campaign that includes some fantastic additional suggestions for screenwriters as to how to be more eco-friendly when dealing with drafts, notes, etc. While most studios have pretty rigid guidelines about formatting, he brings up several ideas writers can adopt for their own printouts.
Two of my favorites include printing 2 pages per sheet instead of one when doing a draft print for personal editing (this is different than double-sided printing), and using "dirty paper." Intrigued? Check it out for more info: