Treo Plus Two
Two months ago, Dan Bricklin wrote so glowingly about the Handspring Treo, a Palm PDA and cellphone, that I bought one -- even though I was among the last holdouts to use a cellphone. He still likes his Treo a lot. So do I.
I use the belt clip, and find it provides very adequate protection (and I'm unusually clumsy). The device hasn't been broken or even badly scuffed yet, despite a number of long trips and a general lack of care.
PDAs need to be considered as expendable. First, they're obsolete in two years, three years at the outside, so there's no point in nursing them too strenuously. More to the point, they don't do you much good if you leave them at home.
I confess that I haven't found much use for SMS messages yet.