When the students finish projects early in my class I allow them to use the computer (Kid Pix and a variety of art games from the web).
There is also a list of sketchbook ideas posted in my room that they can choose from...or they can draw whatever they like in their sketchbooks.
A favorite is allowing them to make their own little sketchbooks...I provide all the materials and leave boxes of neat scrap materials for them to collage with.
I also find that Middle Schoolers are always very eager to help the art teacher...so whenevr I need help displaying or labeling artwork...they are always willing to take on the task!
We make Reference Binders in the beginning of the year (as a homework assignment) where they have to make 10 seperate subject areas (such as flowers, cars, seascapes etc.) so that they have a constant source of inspiration for their work. When they finish early, the kids love looking through magazines or printing pictures off the computer to add to their binders.
Hope this is helpful!
Kara in Northport