So, I was thinking yesterday about phones.
There's 2 kinds, Cellphone and Telephone.
Cellphone
The cellphone is basically an item. You spawn it. When you spawn it, you use it by clicking. When you click, a list of people with cell phones will appear. You can choose who you want to call. They can accept the call or decline it, if they answer it you can talk by say /cellphone messagehere or something. If you want to hang up, you say /hangupcell.
Telephone
The telephone is just like the cellphone, except it has different commands like /telephone messagehere and /hanguptele. It is also connected to something, so you can't go too far from the spawn without the telephone going back to the spawn.
This is like Azerath's idea, but not exactly the same.