You can add your signature to PDFs using your Mac.  Sign official documents using your own hand-written signautre.  Sign business letters, tax forms, or any other document requiring your signature.

I rarely have access to a fax machine and have found that most places will accept my documents when signed using this method.

First, open Preview and navigate to Tools > Annotate > Signature > Create Signature from FaceTime HD Camera

Sign your name on a sheet of white paper using black ink, and then hold it in front of the iSight camera.  Make sure your name rests on the blue line for best results.  You will see a digital preview of your signature on the right.  When it looks good, click Accept.

Your signature will be available in the menu now.  To insert it into a document, click the Edit button and then select your signature from the pulldown menu.

Once you re-size and place your signature, save the document and send it!

If you need to add text to your document, like your printed name.  You can click the textbox icon to insert text anywhere on the document.  Some PDF forms will also have pre-made text fields so you can try just clicking in it to type.