I just discovered the iOS 4 Group Messaging feature and was wondering what kind of limitations people have run into with it. Group Messaging is enabled in Settings->Messages and appears to be off by default. I was testing it and was able to send a text-only MMS to 2 people (both have iPhones with this option enabled) and when each of them replied to the message we could each see everyone else's responses like a chat room. My previous experience with sending an SMS to multiple recipients (with the Group Messaging option off) would cause everyone to be in an individual conversation with only me, unaware that it was a group message. I have recently been using the Beluga app to accomplish group messaging, but it appears that I could just use the Group Messaging feature within the Messages app. I've only tried this out with AT&T iPhones and was wondering what other phones it would work with. Pretty much everyone I text with has either an iPhone, Blackberry, or a quick messaging phone. Has anyone been able to use Group Messaging with any or these types of phones? What about Android phones? Is there a carrier dependency?