Organizing Leveled Readers

My school uses the Reading Street program.  For those of you that use it as well, you know there are a lot of materials to manage.  For example, the leveled readers.  There are six units with five stories each.  So that is thirty different leveled readers.  And there are six of each book and three groups.  In all that is 540 books (if my calculations are correct).  We all know that those cardboard units they came in don't always last and they are an awkward shape to try to store.  I wish I could take credit for the following idea but sadly I can't.  This organizational gem comes from the mind of my wonderful co-worker, Brooke.  She put the six leveled readers from every story in a quart size ziploc bag.  Then she printed labels that said "Unit" and "Story".  You stick the label on the bag and write the unit number and story number in the space provided.  When you finish all that, you put the bags in order into a basket.  I have three baskets- one for each reading level group.  The books I need for guided reading groups are always right there in the front.  At the end of the week I put the books back in their bag and put the bag at the back of the basket.  That way by the end of the year, Unit 1 Week 1 is back at the front again.  Isn't Brooke a genius?