I don't believe there is, but there are things he can do. He needs to put
signs in all the neighbors boxes with the kittie's picture. Call the pound
and put an alert out or better yet, go down with a picture. He should go out
at dusk and dawn, when cats are most active to call the kitty. Also,LOOK UP.
Many lost cats are stuck in a tree. Check any basement window wells in the
area. If  you go out at dusk or even after dark, a flashlight can flas off
of their eyes making them more visable. HTH.

I saw a website a while back, where people were seling radio-tlelmetry
devices for people to track their pets - similar to those things naturalists
use to track whatever animal it is they are studying at the time.  Pet wears
a collar with a transmitter on it, and owner has a handheld device that
tunes in to the signal the collar emits.  They even had multiple-collar
units for multiple-pet owners.  I looked again for the site, but it's been
too long and it's dropped out of my browser's history, and Goggle didn't
find it either (or else I didn't look hard enough).

I haven't heard of anything like that.  But, I do want to add one thing to
the advice others have given you.
When my cat went missing, I talked to as many people as I could in the
neighborhood, and gave them fliers with a picture of my cat.  This was
instrumental in me getting him back.  One of my neighbors spotted him over a
month after he disappeared.  I set a trap in that area, and the next day, I
had him.  If my neighbors hadn't been on the lookout, he might not be here
today.