i have seen this type of thing offered on tv. it is basicly a crayola that you rub off into the scratch and then you wax over it to hole the crayon on the void. bad things about that is your paint is probably not going to be the same as the one on the stick which means that will make for a big streak where the scrtach mark used to be.

i would suggest getting a professionsal car detailer to try and buff it out and last resort would be a good wet sanding. if that doesnt work then get someone to key the damn thing again and pay your dedeuctable for a nice shiny paint job.