Hi Ed,
This is perhaps too simple, but my iPod Earphones measure 37 mm from the buds to the start of the bifurcation,  plenty of length to the back of your neck, but I don't think this is the solution you were needing.
But where is the start of the bifurcation that you need? From your neck or in a pocket?

I see your address is UMich; surely someone in the engineering faculty can provide a solution     (-:
------------------------
Regards from brianF
===============

On 11/04/2010, at 8:13 AM, Ed Wall wrote:

> Hello
> 
>    
snipped

> So my question is does anybody know of a reasonable brand of earplug that either has somewhat longer than usual bifurcating strands up to the ears or can be (as that Radio Shack pair)  moderately easily modified to have such. There must be a pair out there.
> 
> Ed Wall