While Java has yet to fully live up to its "write once, run everywhere" promise on the client side (remember the browser Java wars?!?), it's clear that Sun is intent on being a major player in the wireless world. The ability to support thread management, advanced user interfaces, and local storage separates Java from other mobile technologies such as WAP. In my next article, we'll explore J2ME's capabilities further by developing an address book application. This will include data storage and retrieval using the J2ME Record Management System.