The Apogee One for Mac USB Audio-Interface is a portable USB audio interface that allows you to make professional recordings on the go. It has a built-in omnidirectional microphone and can record with a microphone and guitar simultaneously. Reviews say that the Apogee One sounds excellent and is virtually identical to the Duet for iPad & Mac
The ONE does not much, but it does everything it does VERY well indeed. It fits my mission of practice companion and idea sketch book perfectly. The very portable form factor is just the icing on the cake.