Dell Axim
Windows Mobile 5.0
This was the best of the off-the-shelf PDAs, but for some reason Dell decided to stop selling them in Spring 2007. They now resell some made by Asus, Pharos, and Socket but I don't know anything about them (other than they appear to be more expensive than I would have guessed).

HP iPaq 5915
Windows Mobile 5.0
This is a current (but aging) unit from HP that includes a built-in GPS and road navigation software. I have one and like it. I use it for most of my development mostly because it can charge and connect over a single USB cable at the same time (one less charger/cable). It's *great* for trips and even though the internal GPS antennae is probably worthless under canopy, it has a bigger battery than most PDAs since they expect you to be using it's GPS. Plus it comes with a car adapter so it's one less charger to buy. The speed is ok, the screen is ok, and it feels ok in my hand. The power button is a little funny (it's a tiny button on the side so you can't turn it on inside an otterbox) and I have to press it a few times to get it to turn on/off. The 5910 is the exact same unit, just sold through different distribution channels. It has a single SD card slot (it's buggy on mine and only works intermittently). It'll probably be discontinued very soon as they switch everything over to Mobile 6.0.

iPaq 111
Windows Mobile 6.0
This is a brand new unit and I don't know anything about it other than the specs look plenty good and it's a bit cheaper than I expected.

Samsung i760
Windows Mobile 6.0
This is a cell phone actually. I got one when I recently killed my old cell phone (dropped it in some wet leaves, not even a puddle and it was dead) mostly so I could generate key numbers while away from my desktop computer and not have to drag around a separate pda. I gotta say I'm pretty impressed with it. It feels good in my hand (good size and heft) and it's pretty zippy. I don't like that it uses a non-standard USB connector, and the cable it came with only does data so I can't charge and connect at the same time. Though there is apparently an aftermarket cable I can get for it that does charge/connect at the same time. But I would never use it for real cruising. It has a much smaller screen than other units and I don't think the battery could make it all day as both a phone and PDA at the same time (might work if you turn the phone part off though). BUT, if you don't plan on doing heavy cruising with it, and/or if you already have one and want to try it first, or are very tight on money and want a new smartphone anyway give it some consideration. With a contract, discounts and deals i think you can get one for about $200.

Juniper Archer
Windows Mobile 5.0
This is a real-deal ruggedized unit. It's waterproof and has a huge battery to get you through the day with ease. It has a SD and CF card slot under a protective cap. You can get an optional extended cap so that you can fit it with a CF GPS card and still keep it waterproof and rugged, though I would prefer a bluetooth GPS myself. It uses a standard mini-USB cable, and includes a USB host port (so you can plug a device into it), though it is also mini-USB so you need an adapter to plug in a memory stick. We have one we bought for sales demos and development, but the boss cherrypicked it out of the bunch for his field unit. It's plenty zippy and feels really good in my hand. Beyond the hardware, Juniper has always been a *pleasure* to deal with.

Juniper AllegroCX
CE.NET
This is a boss unit, BUT it runs a version of CE that our normal development tools don't like so I can't recommend it for PocketDog use. Other than that it's a nice unit with a very nice keyboard (layout and feel- though the keys are maybe a little too smooth, some texture would be nice).. If you are interested in it for use other than PocketDog, make sure your application runs happily on CE.NET first. I don't like that it only includes serial ports on the unit itself, and if you want to connect by USB you have to buy an optional USB charging/dock. Also, I've always had trouble getting it to connect reliably, though I have not heard of other people having this problem (I think my issues are conflicts with all the development stuff I have loaded on my computer).

TDS Recon
Windows Mobile 6.0
This unit was just updated to Mobile 6.0, which I haven't had the chance to play with yet. The original PPC2003 model was a bit buggy (crashed frequently) but they seemed to have fixed that with their Mobile 5.0 version. I'm sure the new 6.0 version is a nice unit. Like the archer it is ruggedized, waterproof and has the option for an extended cap to protect a CF GPS. The prices on these dropped significantly when the Nomad came out. I am actually surprised they updated it to Mobile 6.0 instead of just dropping it in favor of the Nomad.

TDS Nomad
Windows Mobile 6.0
This is a fairly new unit. It has the option for a built-in GPS, though with just an internal antennae I'm not sure how well it works under canopy. It has a very fast processor, but doesn't really seem that much faster than other units since there are other bottlenecks (like memory speed), so I'm worried that the extra speed doesn't really do much other than wear down the battery faster. I got to play with one for an afternoon before having to ship it out and really liked it, but don't know much about it beyond the tech specs.

TDS Ranger
Windows Mobile 5.0
Fully ruggedized and waterproof, if you want to run PocketDog on a unit with a full keyboard this is the one. I personally don't like the keyboard- the feel or layout (it's laid out around the direction pad rather than the much more useful number pad). But that's just me, I'm sure other people are just as likely to love it.

Trimble GeoXT/XM
These are odd units that seem to have odd problems. If you already have one, it'll probably be ok but I wouldn't suggest anyone purchase one brand new. Get the Nomad instead for sure.