Capture Signature using HTML5 and iPad

A canvas element with some JavaScript would work great.

In fact, Signature Pad (a jQuery plugin) already has this implemented.

Here is a quickly hacked up version of this using SVG I just did. Works well for me on my iPhone. Also works in a desktop browser using normal mouse events.

Here's another canvas based version with variable width (based on drawing velocity) curves: demo at http://szimek.github.io/signature_pad and code at https://github.com/szimek/signature_pad.