You may phone from here.
Back in the PMP era (i.e. pre mobile phone) many shops and pubs displayed signs saying " You may phone from here". At this time my parents, one of my sisters and our family all had different types of trailer tents. My father being both an inveterate practical joker and a weekend rallier saw on the television an item on these "new faggled mobile phones". They were the size and weight of a house brick and cost the same as a small car. This did not stop my dad. He made a small upturned box which he painted black and to which he fitted a car aerial. Through a slot made in the bottom he passed the end of the cable of one of his house phones. The next weekend he took his new "mobile phone" to a club rally along with a genuine " You may phone from here" sign borrowed from a shop-keeper friend. Many people came to see their first "real-life" mobile phone and some asked if they could use it to phone the family.