Use a cover slip when collecting assignments. Grade the assignment, record the grade on the cover slip, then pass the papers back to students. No alphabetizing papers for the grade book. You can also see at a glance who didn't turn work in.
Calendar: Great classroom organization tip! Put calendar numbers or words on large rings--everything flips. No more boxes/files to store extra numbers or words. Make a few blank cards on the rings too, so you can change things up when necessary.