Dell make a couple of ruggedised latitude's, good machines I hear and not as much of a premium as the toughbooks. Might be worth a look.
Other than that you could look at Thinkpads, which are solidly made still but not like they used to be in my opinion. Or a Apple unibody (sorry, yes it's a mac but the build quality is top rate, I doubt there's a sturdier mass market machine available today...)