Thanks for the info. This option is now standard with the software update that came out for the kindle a month or two ago.
I still haven't decided on my Kindle Touch whether to have it on or not....I left it off and I don't really notice the minimal amount of ghosting it leaves behind.
EDIT: Can't seem to delete my post but I notice the link you posted is to the software update I was referring to....so my post becomes rather useless