Gestures without Libraries, Toolkits or Training: A $1 Recognizer for User Interface Prototypes
Wobbrock, J. O., Wilson, A. D., and Li, Y. 2007. Gestures without libraries, toolkits or training: a $1 recognizer for user interface prototypes. In Proceedings of the 20th Annual ACM Symposium on User interface Software and Technology (Newport, Rhode Island, USA, October 07 - 10, 2007). UIST '07. ACM, New York, NY, 159-168.
Online demo and links to implementations