I’m anxiously awaiting a Google Voice invitation :)
I have a few thought for the usage. One thought would be to have one “emergency” number tied into to a bunch of phone numbers. Example would be an elderly person with a “I’ve fallen and can’t get up” device. The operator calls the Google Voice number and it dials numbers for ALL kids automically, unand one of them picks up. This would be faster then dialing one at a time.