Other than your boarding pass, there is not much information that really needs to be on paper when you’re traveling — for business or pleasure.
Before you leave, put your reservation numbers (car, hotel, etc.) on your smartphone. You can use an app like TripIt or you can use your notes from Outlook. (You could even use a Google Document, if you’re on an Android.)
Even driving directions can be added to your phone ahead of time. Just enter your route and bookmark it in your smartphone’s browser so you can pull it up with ease.
Just a little planning ahead of time helps smooth the trip ahead and cuts way down on wasting paper.