Use an old cell phone charger and a usb socket extention cable to make a wall charger ( this does not come boxed with the zen micro and costs Â£30 ). This is very easy to do.
Step 1: Get a cell phone charger, one that will charge at 5 volts ( the usb voltage ) it should say this on the charger. I use one from a Sagem myV-55. Cut off phone input socket and expose the wires.
Step 2: Get a USB extension cable with a Type A female socket on it, cut off the Male socket and expose the wires.
Step 3: On the phone lead the Red wire is power and the Black is earth ( use a multimetre to double check )
Step 4: On the USB the Red and the Black correspond, cut the White and Green back out of the way they are not used
Step 5: Solder the matching wires together and tape them seperatly, i have also use heat shrink tubing (put it on the wire before soldering)
Step 6: Plug in and your ready to go, this worked for me no problems and took only 15 mins