Someone else mentioned medical devices, and I definitely think that's a great area. But most folks I meet who want to do hardware are going after the consumer market, which is a hard business to enter as a startup.
Of course, what made it really valuable was the software in the box.
Anyone else in medical diagnostics?
Essentially, it's a fancy thermometer.
He's built a video game console kit. hardware is complete, software mostly done, teaching material still to come. What it aims to do is take you through the steps required to build a game console, from how to get a signal on the screen, how video memory and sound etc work right up to building games.
It's mostly about industrial design. There's often some cool stuff on there.
But alas I have no hardware skills so I will have to wait till someone else does it. :-)
I also had some designs for a powered wheel with two degrees of freedom, without a caster, to remove some of the angular momentum problems that classic approaches face.
One idea struck me the other day: why not use your iPhone (or Android phone) as a home phone handset, when you're home and in Wifi range? That would require a specialized base station (perhaps running a stripped-down Asterisk) that recognized when your phone was in range, and would "ring" it on demand, let you pick up your home phone any time, etc.
http://www.logitech.com/index.cfm/keyboards/keyboard/devices...
Rocks pretty good for media. Can't play serious games with it, though. (My girlfriend manages to use it for Portal.)