Motorola has tossed its hat into the rugged ring with the release of the MC55 Enterprise Digital Assistant.
The MC5590 (that's it on the left) is without a cellular radio but sports a 320x240 touchscreen, a 2400mAh battery, Windows Mobile 6.1 Classic, XScale PXA270 processor at 520 MHz, 256MB ROM/128MB RAM, microSD, a 2.0MP camera with flash and autofocus, laser scanner ... You get the idea. The MC5574 is basically the same thing, only with Windows Mobile 6.1 Professional, a GSM/EDGE radio and GPS added in.
Sure, it's not a phone you'll be picking up in a story anytime soon. But if you're in the market for something on a job site, you definitely could do worse.