Pretty neat, that. Only thing that I think less than ideal here is the moisturizing of the pen tip. I think it leaves the touchscreen a bit slimy that way I wonder if it would be possible to use some already conducting material for the sponge tip? You know, the kind of foamy stuff that is sometimes used to pack memory modules and other sensitive electronic circuits.
scrap open a old unused remote or gamepad and use the black thing in buttons