Still fairly new, fairly exclusive, and fairly expensive toys to simulate the 'feel' of 3d surfaces. This company http://www.sensable.com/haptics/products/phantom.html produce one of the few commercial systems around. Specific applications include surgery simulation (it allows students to feel what its like to do a biopsy for example), and sculpting in virtual clay. There was an article about this in 3d magazine, before it went exclusively online.

Sometimes referred to as haptic feedback.