I'd love to have a Scanning service at the Dealers Den/Artist alley/ConOps.
You donate a euro to charity and you get your artwork scanned for you. Then either put on a USB stick(that the attendees bring) or a dropbox file (but that would cost an extra 1 euro for the trouble ;3).
I don't know about the others.. but I have 6 sketches left from the previous years that are not scanned yet + this years sketches. So thats an easy 10-20 euros for charity.