But I'm not here to write about what great devices PDAs have become, rather to address the complexity of connectivity issues they present when building applications and, even more so, when extending those applications to your workforce.

Many handheld applications are single-user and don't require communication with any back-end system (we've all, I'm sure, played solitaire in our down time). However, PDAs need to network for the same reason computers initially did: In order for business applications to be efficient, they have to be able to communicate with one another. Data needs to be shared.

Currently, there are two ways a handheld can communicate with the Internet or company back-end system: 1) through the user's PC (via a cradle or similar connection) or 2) through a wireless modem and service. There is a time, place, and relevance for both of these options. For example, I'm at my computer for at least part of the workday and can synchronize through my cradle at that time. The cradle is a great way for me to get updated information on my handheld and to back up my data. But what about people who aren't at their computers regularly? Are PDA enterprise applications less useful for them? Certainly not, as they can use one of a handful of wireless services.

However, wireless network service is still in its infancy. While coverage, pricing, and processing speed will certainly improve in the years to come, today's reality is that data rates are poor at best and coverage is patchy. To build an application that relies on a wireless connection to your back-end is flirting with disaster. Furthermore, for many individuals and enterprises, spending $50-$100 or more per person per month for wireless connectivity may not be justified by the potential benefit of mobile connectivity.

Infrared: the common denominator
The industry is addressing these issues by offering more connectivity options with varying costs. Palm is releasing a Bluetooth expansion card. 802.11 add-ons are in development. Converged devices will be able to act as an at-will connection. However, choosing a wireless technology on which to build business processes can create a headache, and asking these to be true to their proposed value can be risky. Every day you can read a new expert opinion on which wireless is going to win. But it's not that kind of race. In fact, all these solutions can easily live side by side in harmony. But what happens to the millions of users who have already invested money in a Palm Vx? Or in a later device free of add-ons? There is one thing these all have in common, and it's a wireless form of information exchange that people often overlook: IR (Infrared).