So here's a little idea that just popped into my head, decided to voice it.
When you're following someone, if you click somewhere on the map then that place will appear to the group leader with "[name] suggests a destination" or some such. Then the group leader can choose whether or not to set that as their destination.
Obviously, you'd need some sort of anti-spam defence for this (maybe just a minute or so of cooldown?), but it should prove to be quite useful.