Made to work with Apple's Dock Connector-equipped devices, as well as other companies' Micro-USB-based accessories, Macally's Dualsync ($25) is a convenient way of toting around an extra USB cable. The total length comes in at just under two feet, but it retracts down to about 4.5". Unlike prior retractable USB charging cables, Dualsync includes a detachable head that allows you to switch between the Dock Connector and Micro-USB plugs.
