One of my PDA pet peeves is how the connector and adapter interfaces keep changing. In my recurring PDA nightmare, buying a new handheld has often rendered obsolete my previous investments in PDA accoutrements.

Here's my road warrior dream: to use my PDA instead of my notebook as a general purpose computing device when traveling. A major impediment to this goal has been the keyboard. The optimal PDA would allow me to easily create detailed e-mails and large documents. Built-in thumbboards and handwriting recognition technologies don't cut it for serious wordsmithing. For that, I'm willing to take along a compact, folding keyboard that serves as an alternative, high-speed input tool.

During the past year, I've tried a variety of handheld computing devices and collapsible keyboards. These keyboards, most of which are members of Targus' Stowaway brand, are device-specific. I have one for an older iPaq that doesn't work with the newer iPaqs. I have a Targus Stowaway keyboard for an old HP Jornada, another for a Nextel i95cl phone, and a Flexis FX100 roll-up membrane keyboard (see image) that works with my BlackBerry. That last combination proved unworkable because the BlackBerry is ill-suited to creating anything other than e-mail documents and light memos. Also, my typing speed and accuracy dropped significantly with the FX100 keyboard's tiny keys.

I was growing weary of collecting new keyboards. For some PDAs, external keyboards weren't even available.

Because I was very happy with the Stowaway keyboards, I asked Targus if they had anything to go with the Handspring Treo 300 that I'm currently testing. Targus presented me with their prototype for a new $79 collapsible keyboard that works not only with the Treo, but with any Palm- or PocketPC-based device with an infrared port. The keyboard uses infrared to communicate with the handheld, thus bypassing any physical interface problems.

Unlike its predecessors, which were predominantly two-layer clamshells, the Targus Universal IR Keyboard has three layers (see image). One layer is the PDA mounting and infrared interface layer; the other layers each make up one half of the keyboard. The PDA mounting layer has a spring-loaded grip for holding the PDA; an infrared sensor mounted on an arm that swivels 210 degrees around the PDA's periphery to accommodate just about any positioning of the PDA's IR port; and an easel-like angled surface on which to rest the PDA (see image).

When collapsed, the Universal IR Keyboard's dimensions are 5.6 x 4.2 x 1 inches, making it bigger than most PDAs. Even so, it fits my bill for portability.

Using the keyboard with either a Palm- or PocketPC-based PDA requires the loading and activation of the necessary drivers into the PDA. In my tests with the Treo, driver installation was uneventful (a good thing). Next, I mounted the Treo 300 onto the keyboard and started typing. Compared to the functionality of a full-sized keyboard, I would rate the Universal IR Keyboard as passable, but not nearly as good as Targus’ previous collapsible keyboards.

My biggest complaint is the size of the right side shift key, which is smaller than the alphanumeric keys. As a touch typist, I'm used to a much larger shift key. With this one, your aim has to be near perfect. The small backspace key is another key that will take some getting used to if I'm going to type effectively with this keyboard.

The keyboard's right edge does include hot keys to support fast access to commonly used Palm and PocketPC applications. I would have preferred Targus to use the limited real estate for bigger shift and backspace keys instead of those hot keys. (I would have been happy to use my stylus to occasionally change applications.)

Another design idiosyncrasy is the way the space bar is broken into two smaller space bars, with a decent gap placed precisely in the spot where my thumb is accustomed to landing.

If you're looking for a keyboard that can survive the unforgiving PDA upgrade cycle, and if you can put up with some oddly sized keys, this new offering from Targus could do the trick.

In the coming weeks, I'll be testing the keyboard with a variety of PDAs.

What's your ideal mobile configuration? Use ZDNet's TalkBack below to share your thoughts and ideas with your fellow readers or write to me at david.berlind@cnet.com.