This has been bugging me for a while, too. Jobs is given (and quite frankly, claimed) credit for far more than he deserves. The sad part about that is that it actually detracts from the many tremendously significant contributions things he did make. But as far as invention goes, I don't think Steve Jobs actually invented anything other than, well, Steve Jobs.
That said, this story is about an invention that Steve Jobs _doesn't_ take credit for. It's another example of how Isaacsons biography gets simple facts wrong by simply quoting people without doing research (just like the NeXT quote by Bill Gates discussed earlier).
Also, I think Steve Jobs comes off as belittling the accomplishments of Woz here, by saying that the power supply was just as revolutionary as the logic board, which apparently is clearly false.
While he did invent lots of stuff, I think it's pretty undisputed by the people close to him such as Jony Ive and Andy Hertzfeld, that Steve was famous for claiming other peoples ideas as his own.
[Edit: Jony Ive describes this in chapter 26 of the biography. See folklore.org for more examples.]
It's called a design patent. It explicitly covers only the ornamental, non-functional design of the object, and is subject to somewhat different terms than a utility patent.
In terms of IP law, it's actually quite reasonable.
appreciated, however I don't think that people mean "design" as in aesthetic design when they say "invented"
for example, the spinning beach ball is patented... I think we have passed the point where "patented" has anything to do with what people think of as "invention"