I thought the "ping my keys" was cool until I took out my phone and asked Siri to "ping my keys" and it worked (I do have the iOS beta with the newer Siri fwiw if you try and it doesn't work).
The noise is useless, however, I've been "within a foot" of the keys for 5+ minutes trying to find them - often the best is to have one person start moving things whilst the other watches the phone and screams when it says "it's moving".