So, this afternoon I came across a hearing aid in the street. I can imagine that this is an expensive (and potentially devastating) thing to misplace and I'd really like to try to get it back to it's owner.

I'm scratching my head trying to come up with ways to do this though. I thought I'd put up a few signs in the street but other than that, can anyone think of some good avenues to try to alert the owner that I have their precious hearing aid?