I have found this to be popular with parents, kids, and staff members. It also alleviated some shelving space issues to use the top, although unfortunately the tops of our shelves are rather high off the ground due to space issues on the floor.
|Our picture book section|
For a slightly more expensive option, you could also check out what I did with the series books at my library.
Incidentally, if you are wondering what is up with the cracks in the wall behind the shelves, the top half of that wall is actually sheets of corkboard, not drywall. The signs are laminated (hence the shininess) and then stapled to the cork.