Re: digging up lawns
Put a "winged keel" on a modified whacker packer and you have a machine (featured on The New Inventors a good ten years ago) which pulls cables or pipes through the soil with no need for any trenching at all. You could quite literally run a line beneath a bowling green, run a roller over it and be playing on it within the hour. IIRC it would also work beneath concrete through a slot not much wider than an expansion joint.
For the average suburban property, it would be two hours or less to change over from copper to glass.