Systems, methods, and computer-readable media process and distinguish user input device gestures, such as gestures input via a pen in a pen-based computing system, e.g., to quickly and reliably distinguish between electronic ink entry, single taps, double taps, press-and-hold actions, dragging operations, and the like. Systems, methods, and computer-readable media also are provided for dynamically calibrating a computer system, e.g., calibrating a displayed input panel view based on input data recognized and received by a digitizer. Such systems and methods may operate without entering a dedicated or special calibration application, program, or routine.