I work in a 3-5 school and have independent check-out for fifth graders.  They have a shelf marker ( a paint stirrer from Home Depot) with their barcode on the end of it.  They use a scanner that I set up with a lap-top on the other other side of the circ desk.  They love it.   Also I have a library club that I'm beginning this year with all interested students.  It meets after school to create signage and learn new ways to make their media center their own space.  The more ways to give them some choice in their surroundings, the easier it is to teach!

Hope this helps,

Mary Ellen