I am not sure why iStock and Getty would not except a digital release, digital signatures have been around for years. The digital signature act was passed in the late 90's and we have been signing a digital signature for parcels, credit card transactions, mobile sales for many years. It sounds a bit backwards that they take this stance, check out iRelease, its the best model release App on the market at the moment, its fast, fully customisable and instantly backs up your releases to an online account.  http://itunes.apple.com/au/app/irelease-lite-model-release/id378237352?mt=8  www.ireleaseapp.com