The audio mixer company Behringer has announced three new units set for release, and this company has borrowed a little bit of hardware from Apple: they use the iPad as an interface. As you can see above, the new Behringer mixers make full use of both the standard mixer console controls, as well as Apple's tablet, sitting in as a touchscreen-based software mixer.
Obviously, the iPad doesn't have the hardware to handle all of those audio inputs, just in terms of the ports needed. But it is a very powerful computer with a bright, beautiful touchscreen that makes it easy to build and distribute software, so it's actually an ideal device for this kind of thing, when used in conjunction with that dock connection.
We've seen the iPad used in a number of different industries in this way, from home automation with Savant to plenty of different medical industry uses. Just a few years ago, these companies would have all had to build and design and manufacture their own touchscreens for these products, but with the iPad, there's already a relatively cheap alternative that most sound engineers and other professionals already have access to.