That sucks.
It's too bad a person can't call Garmin with their serial/model number and have Garmin "ping" the lost GPS. Giving a person the exact location. I think this would be a great add on to their services. Just register it to their website and if you lose it, just contact Garmin and have them ping the lost GPS.
I know they don't have radio receivers like phones, but I bet the technology is already out there. Heck, I bet some smart kid can even develop and app for it.
Hope your GPS shows up!