Chances are you have at least one cheat sheet with all kinds of formats and shortcuts written on it, maybe even some sticky notes, information on who to call in certain situations, processes and guidelines (all of the above?). Paper. Some refer to it as "just-in-time information" or "on-the-job tools." Yes, they come in very handy. Still paper. You might even make copies to share with your colleagues. More paper. Or do they create their own? Even more paper.
Let's face it, it's not a very "Green" thing to do. Plus, if you're not distributing copies of your notes, others are missing out on what are probably some really good tips and tricks, which is also a very bad thing. Think of the time spent writing things down, making copies, etc.
A great, easy way to both share information and "Go Green" is to create a wiki for your office.