LAST EDITED ON Aug-27-11 AT 07:57AM (MST)[p]The easiest way is to buy a Wacom pen tablet. They start at around $70 bucks. I'm sure you can find a used one on craigslist, etc., for cheaper. They work great for photo editing as well.
did you try signing it with a felt marker on a piece of paper. Sign it really big. Should be albe to scan it in and just delete the white behind the black signature.
