If you really want a cradle, go for it and good luck finding one (did you try calling Pansonic parts?).

But the cradle doesn't allow you to do anything you can't do without the cradle.

A/V In and Out are available directly from the front panel jack using the same AV cable as the cradle and you can plug the power supply directly into the power jack on the front as well.

I could see the cradle being useful if you want to leave it attached to your display all of the time and drop the AV100 into it when needed, but I'm always taking the power supply and AV cable with me when I take the AV100 somewhere, so the cradle is not conveneient unless I buy another power supply and cable.