How Do I Add My Signature To Documents In Preview In OS X Lion?
Open the document that needs your signature. Click the Annotate button then the Signature pull-down below it. Select "Create Signature from Built-in iSight". Preview will then give you instructions on how to sign your name on paper (black ink, white paper) and will ask you to hold it in front of the camera for capturing. Use can check a box to save the signature for future use in other documents. Now, any time you need your signature you can go back to the Signature pull-down and choose your saved signature.