Apple's newest iPod Nano enables you to go to a random song by shaking the device, something that SonyEricsson introduced about a year ago on their W910. It seems quite a natural way of interacting: the gesture symbolizes what you want the product to do. It's like shaking a sweetener holder to randomize the content, with each sweetener tablet being a song (uh well, ok, with sweeteners it doesn't really matter which one you get, but you get the idea...). It's a manifestation of what some people call tangible user interfaces, in which a person interacts with digital information through the physical environment.

The notion of shake control for digital media players was patented by a company called Outland Research (seemingly the same company that recently patented smart soles for adjustable shoes). So I guess that either Apple and SonyEricsson 'lawyered-up', or have their own - slightly different - patents, or someone is making quite some money from Apple and SonyEricsson implementing shake control.
Interacting with the MusicCube (Bruns, April 2005)

But it seems there's a catch to that patent. Now, I'm no intellectual property expert, but as far as I know a condition for getting something patented is that it is novel, which means the notion should not be in the public domain by the time the patent was filed. So I am somewhat amazed that the provisional application of this patent was filed in November 2005 and it was awarded in 2006, while this paper on the music cube, which proposes and shows the viability of shake control for digital music players was published at the April 2005 SIGCHI conference; a not completely obscure and unknown institution.

More uselog posts on tangible interaction:
> Ten examples of daily tangible interaction
> Tangible interaction: design strategy for usability
> Tangible interaction prototypes at IDE
> MusicCube: a tangible interaction concept for music
> Emotional intelligence in design: thesis defense of Stephan Wensveen
> Rich interaction camera: thesis defense of Joep Frens

(picture at top from areamobile.de)