That’s not bad.
+1 I was thinking the same thing. Get those last few Nanos while you still can.
The fact that no one has recommended a BTU shocker astounds me.
Have you looked at the Nite Ize LED Light-Up Collar The advantage I see is that it will be visible from more angles than a hanging tag light. However, even the smallest collar may be too large for your cat.
Those collars are too big and stiff for a cat.
I gave one of these to friend for her dog. She loved it. I would put one on my cat if he a wasn’t an indoor pet.
http://www.batteryjunction.com/niteize-pcl-03-10pa.html
Dip her in fluorescent dye? 
This is the best budget one I’ve seen so far, based on the reviews, but it is a little large (60x46x17mm). The smaller units I think are GSM only so use cell towers for approximate location.
How about a couple of tritium vials on the collar?
Night ize makes lit collars
Some day I’m going to try some EL wire for our pug … except she won’t go outside at night … or in the rain … or when the sprinklers are on … but if I don’t want to go out …
Don’t do that. EL tends to emit high-frequency sound.
Good caution. There are a LOT of sound frequency analyzer apps in the Play Store. Anybody have good experience with any of them and the capabilities of late model phones (Android or Apple)?
You will locate her when she fly’s and sparks into the air. And a audible crack also. You won’t have to chase after her again…ever…just kidding…heehee!