By way of Avi Greengart, I came across Michael Gartenberg's technology classification. It's simple, but I like it:
Stuff you can't carry (ex: desktop computers, DVD players)
Stuff that needs its own bag (ex: business projectors)
Stuff that goes into your bag (ex: notebooks, some Pocket PCs)
Stuff that fits into your pocket (ex: some Palm PDAs, cell phones)
Stuff that's invisible (ex: watches, key chains, clothing)