At the elementary school where I used to teach, our School Leadership Team focused intently on planning school-wide initiatives to encourage reading.  A few events/activities we did were:

• Book Buddies (pairing younger classes with older classes; classes would meet bi-weekly with book baskets from the library and older buddies would read to/with younger buddies; both age groups loved this interaction and special attention from their buddies)
• Visiting authors, storytellers
• Literacy Nights to teach parents how and why to reach with their children and how to make this interaction fun and special  (I am now learning how we needed to expand our definition of literacy to include more than just reading skills)
• Celebration Book events when we recieved shipments of new book orders to allow students, parents, and teachers to browse the newest additions to the collection.  We would serve cake and juice a decorate tables with the new books to make it a real party atmosphere.
• K classes would walk to our local public library branch weekly for a storytime with the children's librarian there.
• Battle of the Books, Jr.  (Although this competition really focuses on memorizing details of books, I tried to make our practice sessions more like book discussion groups where we shared what we'd been reading, what we liked about whichever story we were reading, where we saw commonalities and differences in the reading list choices, etc.  Students usually brought snacks and loved kicking back in the library for this informal time where they felt very special and welcome to be a part of the group.)
• Designing new book covers for old and sad-looking but good books.  I usually kept a table with a display of good books but with worn out or out-dated covers.  Students could select a book, read it, and then come to me for a book cover template, which they could design with fresh illustrations and information.  It was also a good exercise in learning the parts of a cover, what information goes where, considering attractive, eye-catching illustrations, and writing teasers for the flaps or back cover.  Students loved the ownership of having books in the library which they had helped to beautify, and other students loved checking out books which had fresh, student-designed covers.  It was great and free book advertising!
• Mystery Readers on the morning news show.  Competition for classes to guess the voice of the mystery reader.  Winning class got to hang the "Good Ears" banner outside their classroom for the day.
• Reading Police.  I would visit classes unexpectedly and give "Reading Citations" to those caught in the act of reading.
• Read-In.  This was a culminating event at the end of Children's Book Week.  All of the students, teachers, and staff came together in the multi-purpose room to read together.  Everyone brought whatever book, magazine, or newspaper they wanted, and we just read together.  Some brought blankets or towels, so they could stretch out.  Some of the younger kids or kids who didn't often have one-on-one time with teachers, sat in their laps and read together.  This was a once a year event, but I'd loved to expand it to happen more frequently in the future or modify it to be a fundraiser, like Reading Around the Clock, etc.  Kids loved the non-classroom, non-threatening appeal of this time, and to my surprise and joy, they all really did read-- there wasn't any chit-chatting or goofing off.  Great experience!