More and more often, I see them on stages, DJ tables, and anywhere else that someone wants to access the capabilities of computer-based digital audio tools without hauling around a desktop machine. There have been very few options for audio output, however. Primarily, we need peripherals that offer more channels, higher quality, and better connectors than the built-in headphone jack. Finally, there seems to be some new activity in this area. The Powerbook Audio page is an attempt to track what is available now, and what is expected soon.
All information is based on manufacturers' web sites, press releases, and announcements.
I have been using Powerbooks live for many years. The main thing I need is multiple outputs. Just four would be enough to send a main signal to the sound system while listening to a separate mix on headphones for preview monitoring, DJ-style. Introduced at winter NAMM 2001, radiaL will be available later this year from Cycling '74 .