Most people here seems to have a stereo bluetooth headset, eg MOTO H820, and works pretty well with their x50 or x51. I personally don't like the ideas having something hunging aroung my neck and I'm not having a perfect ear can hear much difference between mono and stereo. :scratch_h As long as I can hear something and talk to someone, I'm happy. If you are such a person like me and happen to have a normal bluetooth headset, you can listen to the music and make a skype VOIP call using your bluetooth headset.
I personally experienced some difficaulty using a normal bluetooth headset. After several days reserch, I know how it works now. I'll explain it step by step: (I'm using a MOTO H700 and Dell x50v w/2003SE).
1) Open your bluetooth manager, tap "New", scroll down a little bit, you should see "Hands-free/Headset setup". Don't tap on it until you finish step 2)
2) Pair bluetooth headset with your x50/x51. Hold the big button (Call Button) for 4-5 seconds until it turns purple, open the boom, then release the button. (you can tap "Hands-free/Headset setup" now)
3) Your Axim should find the headset. Enter passkey (0000) and they should connect.
4) Now you will see a shortcut in your bluetooth manager and hear a beep every 5 seconds. It means the headset and the Axim are connected together.
5) Miracle now: Click the Call button and you should hear the voice comes out from your headset. Actually, I paired my bluetooth headset with my x50v several times. I can't hear anything each time until one time I happen to click that button!
Done!