The adapter for the IXUS is highly recommended. Especially when after a long photo shoot, the battery gives up the ghost and you his images sometimes just wants to transfer more quickly on his PC. Unfortunately offers the supplied USB cable from Canon no power supply, so that one is dependent either on the (mostly empty) battery, or even better on the Canon ACK-500 AC Adapter. For me, the cable is directly next to the USB cable directly to the PC, so I've always full power "rüberzuschaufeln" to my pictures.