Possibly you could create a procedures manual for when you are not in the office. You could document what your daily responsibilities are and the procedures for carrying them out. That way, if you are out of the office, or on vacation, it will make it easier for someone to come in and fill your shoes while you are gone.
For your paper files, you could make an index of each file drawer to make it easier for others to put their finger on what they are trying to find.
Look around. Are there things that could be organized better? Can you check with some of your co-workers to see if there is something they detest doing in their jobs that you could take over doing for them?
Use your imagination. I'm sure you can find plenty to do, especially if you ask the right people. I know everyone has something they just can't stand to do in their job and would love to pass it off onto someone else. Good luck and let us know what you come up with.
WhiteSatin 
