Engadget - If you're like Charles Mangin, you love your iPad or Android tablet, but wish it was a little more Wacom-esque. But why wait for hardware manufacturers to bring the styli to you? Mangin has concocted the PressurePen, a pressure-sensitive stylus that plugs into a tablet's audio jack. The peripheral sends a tone to the tablet based on how far the tip of the pen is pushed in. The tone affects the thickness of the pen stroke, helping you alternate the sizes of lines more naturally than on a standard tablet.