We've seen plenty of compact styluses, but Acme Mobile Products' new MicroStylus Jack ($10) now takes the crown as the world's smallest touchscreen input device. Measuring just about 3/4" long, it's composed of a rubber capacitive tip and short aluminum stem -- that's it. The appeal here is that the shaft can be inserted into any standard 3.5mm headphone port, meaning there's a higher likelihood you'll have it on you when you need it. MicroStylus…
