While you’re chatting, you can invite additional friends to join a group chat.
On a chat screen, touch the Menu Key > Add to chat .
Touch the name of the friend to invite.
The friend you invited and the current participants will receive an invitation to a group chat. Each one who accepts the invitation will join the group chat. In a group chat, everyone can see everyone else’s messages. Group chats appear at the top of your Friends list, with a group chat icon.