Sketch.js is an easy-to-use jQuery plugin that allows you to create canvases upon which visitors can draw. It supports multiple browsers including mobile devices (albeit with performance penalties).
jSignature is a jQuery plugin that simplifies creation of a signature capture field in a browser window, allowing a user to draw a signature using mouse, pen, or finger on touch enabled devices (e.g. iPhones, iPads or Android devices).
jSignature captures signature as vector outlines of the strokes. Although jSignature can export great bitmap (PNG) too, extraction of highly scalable stroke movem