I'm in the "Knowledge Management is important" camp, without explicitly stating what Knowledge Management is beyond improving through creating and using knowledge efficiently. To this end, I'm looking for devices that support this goal. I see a PDA (personal digital assistant) and mobile phone as knowledge management tools.
I've recently tried two approaches. The first is an all-in-one smartphone, a phone and a PDA in the same unit. The second is to have a separate phone and PDA connected with Bluetooth.
For all in one units, I looked at the Sony p910, Nokia 9500, Treo 600, O2 XDA IIs and O2 XDA IIi. I wanted ListPro, an outlining list program that I make heavy use of on my old Palm PDA, and I thought WiFi would be important. These two requirements knocked out the Sony, Nokia and Treo. Of the XDAs, I tried the IIi but was disappointed with the speed (allegedly faster than the IIs but appeared in use to suffer from occasional pauses and no faster than the IIs) and the camera (no flash and no zoom make it relatively useless anyway) and quickly switched to the IIs, which is 5mm shorter and has a built-in keyboard.
The disadvantages of the IIs are relatively low battery life (expect to carry a spare battery on a day trip, and a charger for overnight or more), and a relatively bulky unit that you need to keep in your pocket if you're going to be alerted to incoming calls by a vibrate signal. The advantages are a built-in keyboard, a vibrate mode for things like timed task alarms (you're meeting someone but need to be reminded to hand them something or other, a task I can regularly forget without a separate prompt), the all-in-one advtanges of only one charger and one battery, and good integration between the phone and the PDA functions. Any incoming call is matched against your full contact list, although oddly some text messages from a number already in my contacts list didn't show up with the senders name (I have since come across a program that claims to fix this). The keyboard is still the fastest way to write an email or take a note, in spite of clever input systems like fitaly or MessagEase (which are themselves better than tapping on a picture of a keyboard, or using block-style input, or the transcriber which I found too slow and frustratingly inaccurate on even a 600Mhz+ HP hx4700 PDA). The external keyboard also frees up a good 1/3 of the screen from the alternative of an on-screen input method and works on trains and subways with rickety track.
The two problems, size and battery life, are quite serious. It's easy to look at the unit in the store and think it's relatively small and forget that it needs to be in your pocket all the time if you're going to notice an incoming call by vibrate. The battery life is so poor that you could run out of juice before the end of a day-trip if you use the PDA and phone for something like house-hunting (as my wife and I recently did). With those considerations together, you might say, well, it's too early for SmartPhones, wait a while longer and try a Bluetooth connected two-unit solution.
So I left behind the XDA IIs and took up a cheap-and-cheerful SonyEricsson T630 and HP's hx4700 PDA, thinking I might be able to emulate the all-in-one solution with Bluetooth, but gain a smaller in-pocket device and longer battery life. Sadly, it was not to be. Bluetooth appears to drain batteries. An average day of use with a bluetooth earpiece and making calls drained the phone's batteries to half capacity. A PPC program like Informant will dial via Bluetooth from a Bluetooth PDA, but only if the handsfree is not already connected to the phone. The upshot is you can tap on an address in your PDA, dial the number once via bluetooth to the phone, but not a second time without resetting the phone-to-handsfree bluetooth link. So, for me, I don't use it and the integration has failed.
Another idea I hoped would work was to send tasks with reminders to the phone to generate a vibrate alert, simulating the XDA vibrate alert. Ignoring the issue of synchronisation and collecting redundant tasks on your phone, there appears to be a bug on my system since the reminder times got mangled in the process (e.g. 29th March turned into 11th February). The phone only holds 510 addresses, insufficient for my full contact list, so synchronisation between the desktop, phone and PDA isn't going to work, unless I can work out a category-style solution. And you're carrying around three devices - handsfree, phone and PDA.
I find tapping on the PDA screen is maddening, having tried the keyboard of the XDA IIs, and its certainly not the way to capture observations or send polite or friendly texts or emails. I shorten the text to limit the pain of tapping out the message. The screen on the hx4700 is stunning and a pleasure to read. However, with the goal of capturing and reviewing knowledge and information, the IIs is good at capturing and reviewing, while the hx4700 is much poorer at capturing information. I also find the synaptics touchpad on the hx4700 more difficult to steer than the XDA's navigation button.
I did find that Pocket PC appears to be in better shape than PalmOS, as a platform. I like Acrobat for PDFs on the PPC, and Pocket Informant, which one could compare to DateBk.