Well, here's a pretty bold way to advance conservation: a PDF-like file format that can't be printed. WWF files (named for the World Wildlife Fund in a clever bit of branding) are essentially just like PDFs except for that curious lack of a "print" option. They're meant for documents that the author knows can be used just as well without a paper copy - especially in workplaces where the inclination is to print every possible thing before a meeting. Sure, hackers will find plenty of ways around this restriction, but that's not the point. Adding this little barrier, even if it can be overridden, will prevent a huge percentage of those documents from ever being printed - they'll stay digital, and stay green. Nice!