How can you add your signature to a PDF for free (without printing and scanning)?

Another question that needed answering…

I was planning to finish up a post on our wonderful experience with Aerolineas Argentina this evening, but instead got to spend some quality time figuring out the answer to the above question (thanks IRS for taking 4 months to get back to me on my 2006 taxes!).  Anyway, those of you that hang out in offices all the time won’t have much need for this tip, but in the event that you ever do need to sign a PDF and email it back to someone while on the road, here is an excellent tutorial I came across via google (which references some great and easy to get free software):

How To Add Your Signature to PDFs For Free

My thanks to the original author!