Found it! Spent last night googling my little heart out and found a pile of companies that sell the stuff in a variety of diameters. For artsy-fartsy stuff I've found that the larger the diameter of the individual strands the better, so that holes can be drilled using common sized drill bits. Fiber optic diameters are all metric and tend to be expressed in micrometers; so lose 3 decimal places and it's millimeters. Thus a standard 1mm fiber = .0394" dia. This hole isn't any kind of standard drillbit, but a 1.5mm dia fiber works out to just a wee bit below 1/16".
Optical fiber can cost as much as $2.50 per foot (!!) for really high-grade stuff, but what I wanted was the cheapest I could find. I winnowed this down to some 1.5mm dia unjacketed plastic fiber that costs $.20/ft. The kicker is to get these prices you've gotta buy in bulk; i.e. by the spool. So I just bled $452.- plus shipping for a whacking great 2300 feet of the stuff! URL of my source: www.micalighting.com/fiber_optics.html then scroll down to "End Light Fiber".
I plan to need about 100ft of the stuff for my sign project and the rest will be available for whatever comes my way, but that's still going to leave me with a shitload of surplus. So if anyone's interested drop me an email and I'll reel some off for ya; same cost as me, i.e. $.20/ft, then come and get it. Alternately I'll have the spool in my car when I go to BS or BM events so find me at one of these?
Plan B to connect the dots: I'm having an open shop/BBQ day at my digs on June 10. RSVP for that one cuz I gotta know how much food to get on the grill, heh.