Comprised of 3 stereo inputs, an effects send and return loop and a USB audio interface the Keylargo is a simple but effective way to get your multiple keyboard sources into one mix.
The USB interface allows you to take the audio from a computer and mix it easily without the need for a separate interface. The Keylargo also has a monitor and main output control which allows you to easily level your stage monitors against FOH.
More info at Radial Technologies
Older Music Machines & the People Who Still Use Them
Developments for Korg's instrument have been slow but promising.