With iGo chargers, you plug one end into the device's mini USB port. The other end goes into the charger. For iGo, it's a proprietary round connector that goes into a cable that comes off the main power brick. Thus, you can charge your laptop and your mobile device at the same time.

I just switched to it and am quite happy. The only weird thing is that the external LCD display on my RAZR stays lit while charging. This doesn't happen with the OEM Motorola charger, but I don't care.