Ok. Your computer motherboard has an unused 2x5 male-pinned header that serves up two USB ports. [Those are usually there in case you happen to have internal devices that expect to be powered, controlled and/or configured as USB devices.]
And your normal-height computer case has an unused slot in the back.
Who can't use more external USB ports, right? So plop down the $8 + s/h get this thing.
The wires are short. I measured them at exactly 7.5" from base of the USB port to the very end of the wire header. Since the USB Ports actually sit an inch or more above the mobo, in practical terms, you're not going to get much more than 5 inches of reach. If you need an 12" extension cable, look at item cab-167 vended at FrozenCPU. Even the wire color is a match.
There WAS a catch. The female end of this gizmo that plugs into the motherboard was mis-pinned. Swap the pins into the correct location and you're good-2-go.
On the motherboard, the CORRECT pinout for a single USB internal header is:
Pin1, Red, +5v (Power)
Pin2, White, USB- (Data)
Pin3, Green, USB+ (Data)
Pin4, Black, Ground
Pin5, Void (OR an optional, heavier-gauge black wire for SGND, Signal Ground)
I rec'd this gizmo pinned as
Pin1-Red
Pin2-VOID
Pin3-White
Pin4-Green
Pin5-Black
I had to carefully move the female pins around to correct this.
Use the smallest jeweler's (or eyeglass repair) flat-tip screwdriver you can find. Gently and ever-so-slightly lift the small restraining flap in the plastic terminator--the end to lift is found at the lower edge of the little open square that reveals a part of the pin. The pin should slide/drop right out. Then slide the pin into the correct slot. The pin will click in place behind the restraining flap. Don't bust the flap off or ... well, you know.
While this fix is simple enough, you can be sure that thousands of customers created immense amounts of costs and work for the manufacturer and vendors when they simply returned these things after finding the USB ports didn't work.
As such, you can also be sure that somewhere, in some distant part of the world, the worker who built tens of thousands of these incorrectly -- a worker whose only job description was "insert Pin1 as red, Pin2 as white, ..." -- has now returned to a career in agriculture.
UPDATE: I bought another one of these in August, 2011. It came (correctly) pinned as:
Pin1-Red
Pin2-White
Pin3-Green
Pin4-Black
Pin5-Black
I guess the first one was just a one-in-a-zillion dud.