Connecting the USB port of the H2 to a computer allows use of the H2 as a card reader or audio interface.
When used as a card reader, the SD card inserted in the H2 can be accessed directly from the computer.
When used as an audio interface, the input signal of the H2 can be recorded directly by the computer, or an output signal from the computer can be played back via the H2.

These two operations will work in Windows XP, Windows Vista or Mac OSX (10.2 or later).