I've had a bit of a tidying bug recently (about time) and I've been greatly helped by this file. I got it years ago and never used it, but I eventually found it hiding in the loft.
So much tidying involves going through heaps of paper. A lot can be recycled, but I never know what to do with the stuff I really do want to keep, so it accumulates in piles, that then need to be sorted through again...