I hate to rain on the parade but this effort is badly misguided. The reason physical signatures work is not that a pen allows you to render subtle curves more easily than a mouse, but the fact that the laws of physics can be used to bind a physical signature to the thing being signed (because a physical signature can't easily be moved from one piece of paper to another).

The reason electronic signatures are broken is not that the signature doesn't look right, but the fact that nothing binds the signature to the thing being signed. Once I have your electronic signature it is trivial for me to transfer that signature to any document I like, so the presence of an electronic signature proves nothing. Hence, electronic signatures are useless. And good-looking electronic signatures are worse then useless precisely because they look so much like physical signatures but without the actual benefit that physical signatures provide. Nice curves don't make an electronic signature useful any more than an image of a shiny padlock makes a web page secure.

The ONLY way to sign documents electronically that has any actual utility in the face of disputes (which, if you think about it, is the only situation in which signatures matter) is with cryptographically secure digital signatures.