The next killer app was e-mail. Even in the early '90s, a few people were carrying HP 200LX palmtop computers cabled to an Ericsson Mobidem, and happily sending and receiving text-based e-mail via the RAM Mobile Data (now Cingular Wireless) network. The freedom of anytime, anywhere e-mail was indeed irresistible, and we've seen steady progress in that area.

Many newer cell phones include support for short-message service, and it's not at all unusual today to find mobile professionals and even consumers using a wireless e-mail device such as a Palm with a Novatel modem on the Omnisky or similar service. The RIM Blackberry family has also caught on big time. But with the increasing size of e-mail messages, and the addition of attachments, HTML content and even multimedia, e-mail is now straining current wireless networks.

The next killer app was field-force automation, including support for field sales and service professionals. Originally implemented as custom apps, the rise of the Wireless Application Protocol and increasingly standardized transports has led to a proliferation of applications of that type. Such applications are basically a client hitting a database, and the wireless transport is almost incidental. Intracompany communications with mobile staff is as close as we've gotten to a real killer app for wide-area wireless.

But this is now changing, and rapidly. Because the real killer app is not communications within an enterprise, but rather communications with customers. The secret to success in business is to make it easy for one's customers to buy. Tired of being put on hold, only to eventually reach a clueless "customer service" rep? Why not bypass the middleman? Mobile apps can be designed to hit the same databases that the people at the call center use. Need to make an appointment to get your lawn mower serviced? Simple, grab your cell phone or personal communicator and get it done, now.

I think we'll find that mobile commerce is what will drive wireless for many years to come.