Koosh Ball

The Koosh Ball was created in 1988 by a father who wanted a toy that both his five year old and eight year old could throw.  The sound of the ball when it hit the ground is what created its name (wikipedia, Koosh Ball).

"This ball is easy to grasp, stretch, and pull. Also, the ball does not bounce, making it easier to retrieve. Its hair-like features appeal to the sense of touch (Early Childhood Assistive Technology)." Anyone who has ever touch this toy can tell you how stimulating this toy can be.  Because the ball has so much color and textured it helps students who need extra stimulus and dexterity.
Also, they are very easy to integrate into lessons. Passing the ball to show that one person can talk at a time.  Or having them to play with at recess.  The Koosh Ball doesn't look out of the normal, and are very inexpensive.  Keeping multiple balls around the classroom wouldn't cost more than ten dollars. '

The University of Texas at Austiv The college of education learning technology
     center. (2005). Early Childhood Assistive Technology. Retrieved March 26,
     2011, from http://www.edb.utexas.edu/ATLab/Labinventory/EarlyChildhood/
     ec-sensoryaids.php