Tagged

When I was in line for Customs clearance at Dulles, I noticed a sign for Global Entry users.  I had bought that, thinking it would help when I was leaving, but it didn't -- I still had to take my shoes off.  I followed the sign and found myself at a bank of six kiosks, each of which had a reader to scan my passport, and a pad where I could press four fingers for a fingerprint comparison.  I looked into a scanner, which said that yes, I appeared to be the same person. It asked me the standard customs forms questions, and then  punched out a receipt - which let me bypass the hordes of people getting off the plane who were waiting to meet a customs agent.  Hordes? Fun fact:  an A380 can hold from 500 to 800 people. And once I got my bag, that same card let me have this discussion with an agent:

Agent: Receipt?
Me: I hand it over.
Agent: Where were you?
Me: Paris.
Agent: Okay, we're done.

So it was pretty good. Except for the getting the bags part.  500 to 800 people, all clustering around a carousel, looking desperately for their bags.  Lots of uniquely colored bags, uniquely shaped bags, sliding by -- I still remember the one with the bright pink plastic shell, or the one with the bright yellow tape wrapped around it that said THIS ISN'T YOUR BAG.  But for the hundreds of pretty-much-the-same bags?  Yeah, good luck.  After a while I started to convince myself that my bag wasn't the color I thought, at all.

Why aren't luggage tags available that will, say, respond to a pocket sized transponder when they're sliding into range, within about ten feet of you?  SURELY that's possible?