OS X Lion has made digitally signing PDFs easier than ever before. It's been possible to scan in your handwritten signature and sign documents in earlier versions of Mac OS X, but it was a complex process and one most people probably never trifled with. More often than not, I found it easier to simply print out the document, sign it the normal way, and scan the whole document back into Preview using my flatbed scanner.
Lion's version of Preview comes with a built-in signature scanner that makes signing documents far simpler. In the Annotations toolbar you now have an option to create a signature from your Mac's built-in iSight camera. All you need to do is use black ink to sign a piece of white paper, align your signature toward the camera using the
