This thread got me poking around the web for a US source of tape which is both luminous and reflective. Instead, I found a bunch of interesting luminous ropes at:
www.glorope.com
which I could envision using as a safety-strap (loop) for gear, or even a D-I-Y dog collar. They also have high-glow safety sheeting, which is like a cuttable sheet of luminous sticker: 12"x12" is $3.25