In terms of MIDI control and Multi-touch devices, the Lemur was truly king, until people started making their own alternatives - and alternatives that were ultimately a lot more customisable (in terms of it's control abilities and how pretty you want to make it...)This example shows someone using MAX/MSP as an app that works in exactly the same way as the lemur, with multi-touch abilities, a whole load of functions running at once - now if we all had touch screens (and a copy of MAX) we'd all be taking a big step in terms of music/visuals...And I would make mine look far more attractive than this screengrab:
And now an impressive piece of hardware...THE OHM 64
It is a MIDI controller awesomely suited to visuals - with it 64 button square that could be used to trigger a mass of clips, and array of knobs and sliders for layer control, it jsut leaves me drooling (though probably not quite as much as a Lemur).
In reflection of last year again, I posted up an item with the same name at around the same time. It was for the 'Jazzmutant Lemur' - a multi-touch device that sends wireless signals over a network and allows you to control many digital audio workstations - a favorite being Ableton. It is now in version 2.0 with a host of new features.
Due to the expensive (though reasonable I suppose) price tag, I shan't be getting one soon. There is a program, however, that emulates some of the features of a Lemur on an iPhone or iPod touch - it is called TouchOSC. I still haven't been convinced that an iPhone is really a worthy purchase, but this application alone has given me a new interest in touch-screen devices, especially when it comes to live performance in music and visuals (and visuals here too).