Help with Sketch Pad

http://www.ronaldsworld.com/sketchpad.html

that is the link to a sketchpad that i have been working on. Now i think i got it down pretty clean(but pointers would be nice :D), but right now i want to know how to “save” the picture that the user draws and maybe have it added to a gallery that other users and users can access and see on the web. What do you think?