The issues of Wi-Fi on PDAs can be categorized under technology and usage. The technology has progressed to where WLAN can be built into a PDA without having to alter the form factor. However, designing one that will deliver acceptable levels of performance in terms of battery life, signal range and cost is still an issue. Then comes the issue of practicality. Are the tradeoffs in performance and cost worth it for a device that is designed to display content on quarter VGA screens? Which gets to your question on what would be the killer application. Most likely, it would be Web browsing, since PDAs are better optimized for displaying content rather than creating it. In order for the market to expand, PDAs need to evolve to support full VGA displays so that Web content can be viewed without scrolling left, right, up, down. Or, browsers and viewers need to be better optimized so that Web pages can snap down to a QVGA display. Users also need to value the instant-on capabilities of PDAs over the power and flexibility of Wi-Fi notebook computers.