M-Audio Transit USB by dakine
Very portable, lightweight, 2 in / 2 out, USB interface. Two analog line level channels plus optical s/pdif. USB powered.
This was a precursor to the Apogee Duet & RME Babyface, minus the preamps.
Connectors are mini-phone jack, USB, optical s/pdif.
I use this as a s/pdif to USB interface. I can't comment on analog sound.
Drivers are stable and updated.
Other applications include mobile recording, headphone amp, etc.