So this is interesting, especially since i built an app that does this, but you can now text a group of iOS 4.0 individuals from the iPhone.
Make sure you have group text on – go to Settings => Messages and turn Group Messaging to “On”. Then go to the SMS app, add multiple iPhone owners to the recipients, and send away. Everyone will receive everyone else’s responses.
Try it – I have a device, text me and another iPhone owner!
The option is not available on my iPhone 3GS running iOS4. I’m on the Telstra network in Australia. Regards,Shane.