To be more flexible and to have more USB-ports available I’ve also ordered the following accessories at Reichelt:
5 Volt, 15 Watt external power supply
Wall plug/cable for the power supply
USB 2.0 4-port self powered hub (the beagleboard needs a self powered usb hub if you want to connect a lot of devices)
8GB SDHC Card (this is the actual “hard disk” of the BeagleBoard which I will boot Android from)