If you’ve ever tried to send a voicemail to various people at once (you know, that announcement that you'll be late, etc.), you know how much of a headache it is.
You have to go through all those complex options in your voicemail setup for "group messaging", but after you’ve done all that, you realize, “uh oh, I can’t add anyone outside of my carrier!”
www.pinger.com is the way to go.
It’s free, easy to setup, and you can add a bunch of people during the setup. Also, you don’t have to all be on the same carrier.
You can send group voicemails to everyone, and this is often better than group text messaging, because you won't have to worry about the character limitations on texting.