If you've been following Soma Ghosh's articles here on the Wireless zone, you've learned how to use your Java skills to build simple applications for handheld devices. Now how do you link those devices to the outside world? In this article, Ghosh discusses the javax.microedition.io and java.io classes that lie at the heart of J2ME networking. You'll learn how J2ME applications handle URLs and accept input, and even be taken through a sample program that downloads currency exchange information to any network-accessible, J2ME-compatible device.