Not sure what you are asking. If you want to draw with a pen instead of the mouse, you can get a digitizing tablet to replace the mouse, for instance a Wacom Bamboo:
http://www.cdw.com/shop/products/Wac...s/1863474.aspx
This will work with most graphics applications, like paint, but check for compatability with the manufacturer
If you want to draw directly on the screen with your finger or a stylus you need to get a tablet computer, like an IPAD.
I think your best bet would be to contact the author of the blog where you saw this and ask them what they use.