Hey Matt,
My workflow works really well when taking a signature like that to different formats. What I do is actually take the image into Illustrator rather than Photoshop because Illustrator is vector based and allows you to take that final production and scale it up/down with out any quality loss.
Once I bring in the image I select the Pen tool and trace around the signature (also using besier curves), these creates the image as vector and it saves you time because you only traced it once but you can make it any size you want.
Thanks
Wade Johnston
Multimedia Designer
http://www.multus-media.com