An example of a touch illusion is the contingent after-effect. When the thumb and forefinger are slid repeatedly along the edge of a wedge, a rectangular block then handled in the same manner will feel deformed.
Moving with index and middle finger crossed along an edge feels like two parallel edges.
Another is a physiological illusion where with one hand immersed in cold water and the other in hot and then either in lukewarm, the lukewarm water will feel both hot and cold.
wikipedia.org dumped 2003-03-17 with terodump