A Shoe Phone (Gen 1; Bluetooth headset)

Step 2 Make sure the shoes are suitable

The important thing about these shoes is that they have a proper wooden heel (well, this one was masonite, but that's close enough) that could be hollowed out to fit the head set. A quick check confirmed that the head set would be able to fit in the shoe, both in terms of area and also thickness.

Of course, if you got the wrong shoes and then read this step, its a bit late, but oh well.