You can get a USB sync charge cable for home, but note that you will only be able to charge when the device is powered off because the X50 and X51 series are power hogs. See this thread for more details:
http://www.aximsite.com/boards/x50-x...e-warning.html
To charge in the car, just get a car charger specifically for the device. Other chargers (some of the Ipaq ones) may work as well, provided they have the same specs as the one for your device, but will require the AC adapter dongle.