My favourite adaptation, spotted twice in Antwerp, is women who don't have or don't use the handsfree device, but who are comfortably handsfree nonetheless—that is if you wear a headscarf. Simply snuggly fit the upper half of the phone between head and headscarf and off you go.
The main thing that weirds me out about this trend is that it makes it harder to tell whether or not someone is crazy. You can't always immediately spot the wires, so whenever someone seems to be talking to no one in particular, I find myself looking for the telltale earphones. I was waiting to cross the street in Stuttgart and another lady was waiting with me, jabbering away, so I think, "I suppose she's on the pho—"; but no earphones. Therefore probably a little crazy. This judgement call is becoming part of daily life. Of course the answer usually is "on the phone"—not that I can, for the life of me, figure out what is so important that we need to be talking about it all the time.
There is, however, a third possibility. Waiting for a train in Frankfurt, I found myself and quite a few fellow-waiters attracted to this scene: an overly tan, skinny, blond Italian girl, hands in skinny-jean pockets, frantically pacing back and forth, shoulders jerking about, but face jerking about even more, as she has a very animated and seemingly agitated conversation—with earphone wires clearly visible. Aha! Crazy and on the phone.